Providing Safety

Glossary

Definition list

Glossary Machine Safety

It is important to know the terminology used in the world of machine safety in order to ensure a safe working environment for both workers and machines.

This definition list has been compiled to provide you with a clear and concise explanation of important terms, abbreviations and components related to machine safety.

Whether you are an engineer, safety officer, machine operator or just someone interested in the subject, this definition list provides valuable insights to enhance your knowledge. From essential terms such as emergency stop buttons, interlocking systems and safety relays to more advanced concepts such as risk analysis, safety standards and safety categories, we have included a wide range of terms that will help you better understand the complex world of machine safety.

This definition list is a useful tool to expand your knowledge of machine safety and to effectively communicate risk management and safety compliance.

A

ABUS
Abus is an internationally renowned brand specialising in security and safety solutions, including Lockout-Tagout equipment for machinery and industrial applications, such as safety padlocks, safety tags, electrical lockouts and various types of safety padlocks.
Read more about Abus

Access protection
Acces protection is a technology used to detect the presence of persons or objects near machines, often using laser or radar sensors to identify potential hazards and safeguard the machine.

Actuator
An actuator is a mechanical or electronic device used to perform a physical movement or action. An actuator can be used to activate an emergency stop button, operate a locking mechanism or open or close a safety door. Our safety switches can include a fixed actuator, a sliding door actuator, a handle actuator or a lever actuator.

Alcatraz Interlocks
Alcatraz Interlocks is a global supplier of high-quality interlocks. Alcatraz Interlocks specializes in designing and manufacturing mechanical interlocks and machine safety systems, such as valve interlocks.
Read more about Alcatraz Interlocks

Alertness
Alertness is the attention required of operators and workers to work safely with machinery and recognise potential hazards.

Alignment
The process of carefully positioning and adjusting machine parts to ensure that they are correctly aligned and that the machine can operate smoothly and safely. Alignment is important to minimise vibration, friction and wear, extending machine life and improving safety.

Alignment tolerance
Alignment tolerance is the allowable variation or deviation in the position or alignment of machine parts from their ideal position. It indicates how much deviation is acceptable without affecting machine operation, performance or safety. Alignment tolerance is often used when adjusting shafts, gears, belts and other moving parts of machines. Setting the correct alignment tolerance allows the machine to operate smoothly, reduces vibration and minimises wear, which can extend the life of the machine.

Alpha
The Alpha is a mechanical entrapment device  specifically for safeguarding doors. This universal locking system ensures that machines are not unintentionally restarted during operations.
Learn more about the Alpha interlocking device

Alternating Current (AC)
Alternating voltage is an electrical current characterized by its periodic changes in direction and polarity. Commonly used to energize household appliances and industrial systems, it serves as a versatile source of power.

Analog I/O
Analogue inputs and outputs (I/O) refers to the process of converting analogue signals, such as a sensor measurement or actuator operation, into a digital signal that can be processed by a machine control system.

ANSI
ANSI stands for American National Standards Institute. It is a private organisation that develops and promotes voluntary standards for various industries, including machine safety. ANSI standards are widely accepted and are often used as a reference when designing and assessing machine safety.

Arbowet
The Arbowet (Working Conditions Act) is a Dutch law that contains rules and regulations relating to working conditions and safety in the workplace.

AS-interface
AS-interface (Actuator Sensor Interface) is an open, digital communication system used to connect sensors and actuators to an automation system. AS-Interface allows safety information and process data to be transmitted over a single cable. AS-Interface is often used in applications where simple digital input and output signals are required, such as the control of sensors, switches, motors and pneumatic actuators.

A-standards
A-standards are standards for machine safety. They are drawn up by standardisation bodies, such as ISO 12100, which provide guidelines and requirements for designing and building safe machinery.
Read more about laws and regulations

ATEX
An abbreviation for “ATmosphères EXplosibles”, refers to the European directives (ATEX 2014/34/EU) relating to explosion safety. ATEX directives apply to equipment and protective systems used in potentially explosive atmospheres. ATEX 2014/34/EU sets requirements for the design, construction and use of this equipment.

ATEX 114
The ATEX 114 directive, also known as the ATEX equipment directive, specifies the technical and safety requirements for equipment intended for use in explosive environments, including machinery and safety components.

ATEX safety switch
ATEX Safety Switches are Atex-compliant safety switches suitable for use in
potentially explosive environments. Atex safety switches are often used in industries
such as chemicals, oil and gas and mining.
Read more about explosion-proof safety switches

ATEX-zones
ATEX zones are areas classified based on the risk of explosive atmospheres, with each zone having specific safety measures and equipment requirements to ensure safety when working with machinery in such environments. ATEX zones can be divided into two main categories: ATEX Zones 0, 1 and 2 for gases and vapours and ATEX Zones 20,21 and 22 for dust.

Auxiliary reset
An auxiliary reset is a function on a safety switch or system that allows a machine or device to be reset after a safety event has occurred. This could be, for example, restoring an emergency stop button to restart the machine after it has stopped due to an emergency.

B

B10d-value
The B10d value is a measure of the reliability of a safety component, such as a safety relay or safety contact. It indicates the expected number of operating hours before the reliability of the component decreases to 10% (in terms of failure probability).

Blocking force
The force required to block or stop a safety device, such as a safety gate or latch. Blocking force is usually measured and expressed in newtons (N) or kilonewtons (kN). The level of blocking force required depends on several factors, including the risk level of the machine, the speed and mass of the moving parts, and the possible consequences of uncontrolled movement.

Brady
Brady is a supplier of machine safety products and offers a comprehensive Lockout-Tagout product range. The Brady range includes safety padlocks, lock multipliers, tags and labels, interlocks and lockout stations.
Read more on Brady

Bravo
The Bravo is a mechanical entrapment device for securing light curtains. This universal locking device ensures that machines are not unintentionally restarted during operations.
Learn more about the Bravo interlocking device

B-standards B-Standards are standards that apply specifically to machine safety. These standards are drawn up by standardisation bodies, such as EN ISO 13849. These B-standards contain guidelines and requirements for designing and building safe control systems and safety functions of machinery.
Read here more on laws and regulations?

Bypass mechanism
A bypass mechanism is a temporary bypass or shutdown of safety measures to perform certain tasks during that time, under controlled and approved conditions.

C

Cartridge fuse (knife fuse)
A fuse cartridge, is a type of fuse used to protect electrical circuits from overloads or short circuits. It consists of a metal conductor that melts and interrupts when current is too high, interrupting the flow of current to the circuit. A fuse cartridge can be replaced with a new cartridge after it is triggered.

CCC (China Compulsory Certification)
CCC is a certification system that is mandatory for certain products sold in the Chinese market, including machinery and equipment. The CCC mark indicates that the product meets the safety and quality standards used in China.

CE-conformity
CE conformity refers to meeting the requirements of CE marking, as set out in the European Machinery Directive (2006/42/EC). This ensures the safety and health of workers when using machinery within the European Economic Area (EEA).

CE-marking
The CE marking is a conformity marking that indicates that a product complies with applicable European safety and health standards. In the context of machine safety, CE marking indicates that a machine complies with relevant European directives and has been assessed for safety aspects before being placed on the market.

CETOP (Comité Européen des Transmissions Oléo hydrauliques et Pneumatiques)
CETOP refers to an European federation of national associations in the field of oil hydraulics and pneumatics. In the machine safety world, CETOP is used as a standard for certain standards and specifications related to hydraulic and pneumatic systems.

CIP Safety
CIP Safety (Common Industrial Protocol) is a communication protocol for secure data transfer between safety devices and safety controllers in the machine safety industry. By using CIP Safety, safety devices can be seamlessly integrated into existing industrial networks, such as Ethernet/IP.

Circuit breaker
A circuit breaker is an electrical device used to automatically switch off an electrical appliance when excessive current or a short circuit is detected.

Cleaning in Place (CIP)
Cleaning in Place (CIP) is a method used in the food industry to clean equipment and pipes without dismantling them. It uses specialised detergents, rinse water and mechanical action to thoroughly clean and disinfect the interior of equipment.

Coast down time
Coast down time refers to the time required for a machine or system to come to a safe stop after the stop signal is activated. It is an important parameter in determining safety measures and reaction time in machine safety.

Collision Detection
Collision detection is a function or technology used to detect and prevent collisions with people or objects. Or collisions between moving parts of a machine.

Colour coding
Colour coding is the assignment of specific colours to safety components, such as safety padlocks, warning signals and markings. This allows visual information related to machine safety to be conveyed quickly. Colour coding is also commonly used to distinguish between safe and unsafe areas, emergency stops and other safety-related elements in a machine environment.

Committee for Risk Assessment
A multidisciplinary group of experts responsible for identifying, evaluating and assessing potential risks associated with a machine, with the aim of taking appropriate safety measures.

Compressed air cylinder
A compressed air cylinder is a pneumatic component used to generate linear motion. Compressed air cylinders receive compressed air and convert it into mechanical energy to drive machines or components.

Compressed air leakage
Compressed air leakage is the unintended loss of compressed air from a pneumatic system due to leaking connections or other components. Compressed air leaks can reduce system efficiency and lead to unnecessary energy consumption.

Compressed air quality
Compressed air quality is the purity and condition of compressed air used in pneumatic systems. Compressed air quality is important to ensure system reliability and avoid possible contaminants that could affect machine operation.

Conformity assessment
The process of assessing and verifying the conformity of a machine with applicable machinery safety standards and regulations, including inspection, testing, and documentation.

Containment protection
Containment safeguards are mechanical solutions against containment hazards at machines and processes. These mechanical solutions prevent machines from being unintentionally restarted during operations.
Read more about containment protection devices

Control circuit
The electrical circuit responsible for monitoring and controlling the safety functions of a machine, such as safety relays, emergency stop switches and safety sensors.

Control levers
Handles or levers used to enable physical operation of machinery, such as controlling the speed, direction or position of a moving part.

Control panel
The control panel or operator interface of a machine on which control buttons, switches, displays and indicators are placed to operate and monitor the machine.

Control units
The control panel or operator interface of a machine on which control buttons, switches, displays and indicators are placed to operate and monitor the machine.

Corrective action
An action taken to correct an identified safety problem or lack of compliance with machine safety standards and ensure the safety of the machine.

Corrosion resistant
The property of materials or components that resist corrosion or deterioration from chemicals, humidity or other environmental conditions that may be present in industrial environments.

CSA (Canadian Standards Association)
CSA is a Canadian organisation responsible for developing and publishing standards for various industries, including machine safety. CSA standards are recognised in Canada and are often used as a reference when assessing machine safety.

C-standards
C standards refer to the European standards drawn up by CEN (Comité Européen de Normalisation). These standards are based on the European Machinery Directive (2006/42/EC). C standards provide guidelines and requirements for manufacturers, machine builders and users to meet required safety levels.
More on laws and regulations? Read here

Cut-off valve
A cut-off valve is used to interrupt the flow of liquids or gases in a machine or system. Shut-off valves are used as part of safety systems to stop the flow of hazardous substances in the event of an emergency or malfunction.

Cycle time
The time required for a full cycle of a machine movement, such as a flashing light, a door opening and closing, or a press cycle. Cycle time can affect operators’ safety measures and reaction time.

Cylinder lock
A locking mechanism used to lock a machine part, such as a door or a guard, in place and prevent it from being accidentally opened during machine operation.

D

Dead man’s switch
A dead man’s switch, also known as an emergency stop button or an emergency button, is a switch operated by an operator to stop a machine immediately in case of an emergency situation. An emergency stop is designed to be quickly and easily accessible so that the operator can immediately switch off the machine in case of the threat of a dangerous situation.

Dead zone
An area or zone in the working environment of a machine where no safety detection or protection is present, increasing the risk of accidents or injury.

Detection distance
The maximum distance between a sensor and an object at which reliable detection is still possible. Detection distance is an important parameter when selecting safety sensors for monitoring zones or detecting movements near machines.

Diagnostic Coverage 
Diagnostic Coverage is a measure of a safety system’s ability to detect and diagnose faults and errors. It indicates the extent to which the system is able to identify and report faults to ensure safety.

Direct Current (DC)
Direct Current (DC) refers to the constant direction of flow of electric current. It is a type of electric current where the current always flows in the same direction, from positive to negative. In machine safety systems, DC power supplies can be used to supply current to safety components such as sensors, switches and relays.

Direction of movement
The direction in which a machine or moving part moves, such as linear movement, rotational movement, up/down, back and forth, etc.

Disconnection distance
The shutdown distance is the minimum distance that a safety sensor must have to shut down the machine or stop a dangerous movement when a person is near the machine. It ensures that the machine is stopped in time to avoid injury.

Documentation of machine safety
The process of preparing and maintaining documented machine safety information, including risk assessments, technical specifications, manuals, certificates and maintenance records.

Door safety
A mechanical system for locking machine doors. These interlocks are equipped with a safety key. A safety key prevents entrapment in the hazardous area. The key is usually removed and kept by authorised personnel to prevent the door from being opened during machine operation
Learn more about trapped key interlocks

Double excitation
A safety function that requires two independent switches or sensors to be activated simultaneously to enable a movement or action of the machine, reducing the likelihood of unintended or uncontrolled movements.

Downtime monitoring
Downtime monitoring involves taking safety measures to ensure that a machine or system comes to a safe stop before maintenance or repair work is carried out. This can include the use of interlocks, signalling systems and monitoring sensors.

E

Electrical isolation
The use of insulation materials or methods to prevent electrical conduction between conductive parts, thereby reducing the risk of electric shock or short circuits.

Electromagnet
An electromagnet or holding magnet generates a magnetic field when electric current passes through it. It is often used in machine safety applications to keep doors, gates or guards closed and locked until the current is interrupted.

Electronic Device Monotoring
Electronic Device Monitoring (EDM) is a function in machine safety systems that monitors the operation of safety components. It uses electronic circuits and sensors to monitor the status of emergency stop switches, safety sensors and other safety equipment. By continuously monitoring operation, EDM can detect potential faults or failures in safety equipment and generate alerts to ensure system safety.

Emergency release 
An emergency release is used to quickly and instantly unlock a machine or system in case of an emergency situation. An emergency release allows you to bypass the normal locking of a machine and gain immediate access to dangerous areas.

Emergency stop
An emergency stop button or switch used to immediately stop a machine or system in emergency situations. It activates a safety function that shuts down the machine and stops potentially dangerous movements or actions.

Emergency stop circuit
An emergency stop circuit is an electrical circuit that interrupts power to a machine or process when an emergency stop button is activated. The circuit is designed to react quickly and bring the machine to an immediate stop.

EN (EuroNorm, European Standard)
EN refers to standards drawn up by the European standards organisation CEN (Comité Européen de Normalisation). The standards apply within the European Union.

Enabling switch
A permission switch is a switch used to grant permission to start or resume a machine or system. It is often operated by an authorised person and serves as a safety measure to prevent inadvertent or unauthorised activation of the machine.

Energy lockout
A safety procedure in which the energy supply to a machine is isolated or disabled and locked with a specific locking device, this can be a safety padlock or other Lockout-Tagout locking device. This prevents unauthorised activation or operation during maintenance or repair work.

Energy source
An energy source is a system, device or component that provides electrical, mechanical, pneumatic or other forms of energy for the operation of a machine. It may include electricity, compressed air, hydraulic fluid or other sources of energy.

Environmental factors
Environmental factors are the physical and chemical conditions in a machine’s environment, such as temperature, humidity, vibration or chemical substances, that may affect its safe operation.

E-stop (Emergency stop)
Environmental factors are the physical and chemical conditions in a machine’s environment, such as temperature, humidity, vibration or chemical substances, that may affect its safe operation.

EtherCAT
EtherCAT is a real-time Ethernet communication system used in industrial automation. EtherCAT enables fast and reliable data transfer between different devices and control components.

Ethernet IP
Ethernet IP is an industrial communication network standard based on the Ethernet protocol. Ethernet IP enables data exchange and control between different devices and systems in an automation environment, allowing machine safety systems to be integrated with other automation applications.

EX (ATEX)
EX is an abbreviation used to designate equipment or components suitable for use in explosive atmospheres according to ATEX directives. The “Ex” sign indicates that the product complies with explosion protection requirements.

Ex zone
An Ex zone, also known as a hazardous explosive zone, is an area where an explosive atmosphere may develop due to the presence of flammable substances, such as gases, vapours or dust particles. Classifying a site as an Ex zone is important when selecting suitable equipment and protective measures to minimise the risk of explosions.

Explosion protection
Measures and guidelines applied to ensure safety in environments where explosive atmospheres may be present, e.g. near flammable gases, vapours or dusts.

Explosion safe
The ability of equipment or systems to prevent them from forming ignition sources and causing explosions in the presence of flammable substances. Explosion-proof equipment is designed to meet specific safety standards and requirements to minimise the risks of explosions.

F

Fail safe
A design principle that ensures that a system or component falls or remains in a safe state in the event of a failure, such as a power failure or malfunction. Fail safe mechanisms are used to ensure the safety of machines and systems.

Fault diagnosis
The process of identifying and locating faults, failures or defects in a machine or system. Fault diagnosis is important for identifying problems that may affect safety and for taking appropriate corrective action.

Fault masking
Fault masking refers to a situation where a fault or failure in a system is not detected or signalled by the safety system. This can result in reduced system reliability and an increased risk of unsafe situations.

Fault tolerance
The ability of a system or machine to continue operating safely even in the event of faults or failures. Fault resilience can be achieved by using redundant systems, fail-safe designs and emergency shutdown systems.

Feedback system
A system that sends information back to a control system or operator to communicate the status, performance or condition of a machine. Feedback systems may use visual indicators, alarm signals or displays to support the safe operation of machines.

Finger/Hand detection 
Finger detection is a functionality or technology used in safety systems to detect the presence or contact of a finger near hazardous areas or moving parts. The detection of a finger can result in the immediate stopping or slowing down of machine movement to prevent injury.

Food grade
Food Grade refers to materials, equipment and processes that are suitable and safe for use in the food industry. It implies that all components in contact with food comply with specific standards and guidelines related to food safety and hygiene.

Force guided relays
Switches that are mechanically activated and ensure that a certain action must be performed before other actions can take place. Forced contacts are often used to ensure a safe sequence of actions and to prevent unintended actions.

Fortress Interlocks
A well-known brand of safety interlocking systems offering high-quality interlock solutions to ensure the safety of machinery and equipment. Fortress’ products include Safety Switches and Trapped Key Interlocks.
Read more on Fortress Interlocks

FOV
FOV or Field of View, is the open observable area a person/machine/radar can see. Radars can have different fields of view. Symmetrical FOV, and asymmetrical FOV, or a corridor FOV. With different lengths and degrees of the horizontal and vertical planes.

FRANK access control
The tool FRANK by Fortress Safety records the access and access times, allowing for better productivity analysis. Additionally, it gives more clarity on the optimal times to perform preventive maintenance. FRANK may also be used to collect samples and keep track of inspections.
Learn more about FRANK

Freedom of movement
The range of movement allowed by safety devices when working with machinery, where workers have sufficient room to move to perform their tasks without undue risk.

Frequency inverter
An electronic device used to control the speed and power of an electric motor. An AC drive can be used to enable safe and controlled movements of machinery.

Function lock
A safety measure that locks or disables certain functions of a machine during certain operating conditions or operations. Function locking prevents unintended use of functions that could be dangerous.

Functional blockade
A safety mechanism that is activated when a certain function, such as a door lock or light curtain, is interrupted or blocked. Blocking the function prevents the machine from operating until the problem is resolved.

G

Group lockout
A group lockout is a procedure in which multiple energy sources are locked out to ensure that maintenance or repairs can be safely carried out on machines or systems. A group lockout involves disabling and locking each hazardous energy source so that no one can accidentally activate the energy source.

H

Hand detection
Hand detection refers to the ability of a safety system to detect the presence or contact of a hand near hazardous areas or moving parts. Hand detection can result in immediate stopping or slowing down of machine movement to prevent injury.

Hazard
A hazard is a potentially dangerous situation or source that can cause injury or damage. Hazards can include moving machine parts, electrical hazards, hazardous substances and thermal hazards.

Hierarchy of risk reduction measures
An approach in which risks are addressed according to a defined hierarchy of measures. This includes eliminating risks at source, implementing technical safeguards, taking organisational measures and providing personal protective equipment.

Highly encoded
A term used to describe an encryption system that provides a high level of safety. Highly encrypted systems use complex codes and algorithms to prevent unauthorised access or manipulation.

HMI (Human-Machine Interference)
An HMI is an interface that allows people to interact with a machine. An HMI can be used to display safety information, perform control operations and show status indicators.

Holding force 
The maximum force that a locking mechanism or safety device can withstand before it is activated or released. The holding force is an important aspect when assessing the safety and reliability of interlocking systems, such as safety doors or safety interlocks.

HSV (Fluidsentry)
HSV is the Fortress Interlocks Fluidsentry hydraulic safety valve system with electrical monitoring from Fortress Safety. The Fluidsentry HSV system can be retrofitted (retro-fit) into existing hydraulic systems to enable the highest level of safety up to Cat. 4, SIL 3, PLe.
Learn more about HSV

Hydraulic interlock
A safety component used in hydraulic systems to interrupt the flow of fluid and release pressure when a hazardous situation is detected. Hydraulic safety valves can be operated manually or automatically and play an important role in preventing uncontrolled movement and minimising pressure build-up. Read more about hydraulic safety valves.

Hydraulic pressure
Hydraulic pressure is the force exerted by a fluid, usually oil, in a hydraulic system. Hydraulic pressure can be controlled and regulated using valves and pressure regulators to ensure the safe operation of machinery.

Hydraulic safety
Hydraulic safety is the application of safety measures and components in hydraulic systems to minimise risks of leaks, pressure build-up and uncontrolled movements.

Hydraulic safety valves
A safety component used in hydraulic systems to interrupt the flow of fluid and release pressure when a hazardous situation is detected. Hydraulic safety valves can be operated manually or automatically and play an important role in preventing uncontrolled movement and minimising pressure build-up.
Learn more about hydraulic safety valves 

Hydraulics
A technology that uses fluid pressure to transmit or control mechanical force. Hydraulic systems require specific safety measures to control potential hazards such as leaks, pressure build-up and uncontrolled movements.

I

I/O (inputs/outputs)
I/O stands for inputs and outputs. In the machine safety world, this refers to the various sensors and actuators used to receive and transmit signals. Inputs are the signals received, such as from a safety switch that detects when a door is opened. Outputs are the signals sent, such as activating an emergency stop relay to shut down the machine.

I/O Link
I/O Link is a communication protocol used to exchange data digitally between machines, sensors and actuators. It also handles the transmission of safety signals and ensures efficient and standardised communication.

IEC (International Electrotechnical Commission)
IEC stands for International Electrotechnical Commission. It is an international standards organisation that develops and publishes standards relating to electrical engineering, electronics and related technologies.

Industry 4.0
Industry 4.0 is a concept that refers to the integration of advanced technologies and automation into industrial processes. Industry 4.0 includes the use of digital connectivity, data analytics, cloud computing and the Internet of Things (IoT) to improve efficiency, flexibility and safety in industry.

Industry leading practice 
Industry Leading Practice means the best and most advanced methods, techniques or processes recognised and followed in a particular sector or industry. They are the standards and practices considered leading within the industry.

Ingress protection (IP-value) 
A rating system that indicates the degree of protection against the ingress of dust and water. The IP value consists of two digits, the first digit indicating protection against dust, the second digit protection against water. Examples of IP values are. IP65, IP67 and IP67, the higher the digit, the higher the degree of protection.

Interlock 
A safety mechanism that ensures that certain actions or movements can only take place when specific conditions are met. Interlocks are used to prevent unsafe situations by controlling and regulating the operation of machinery or equipment.

Inxpect
The safety radar sensor, the world’s first comprehensive safety solution for monitoring protected areas based on radar technology, is made by Inspect S.p.A.
The components of this approach are a controller and a radar sensor. Complex applications and tough settings, including the outdoors, can be safely monitored with this all-inclusive solution.The sturdy Inxpect radar technology ensures performance in the presence of environmental factors like dust, dirt, rain, light, sparks, and vibrations.
Read more about Inxpect

ISO (International Organization for Standardization)
It is an international non-profit organisation that develops and publishes standards applicable to various aspects of industry and technology. ISO standards are applied voluntarily, but can be adopted as legal requirements in some countries.
More on laws & regulations regarding machine safety? Read here

Isolating switch
A isolating switch is a switch used to turn the power supply to a machine or system on or off. It is a manual switch often used as a means of disconnecting the power source from the machine before any maintenance or service work is carried out. A work switch should be easily accessible and clearly marked for safety purposes.

J

Junction boxes
A Junction box also known as a J-box is an enclosure used to protect and manage electrical connections and wiring of various components. It is a central point where the wiring of sensors, switches and actuators come together before being connected to control or safety systems.

K

Key exchange units
A key change unit is a device used to manage the keys needed to unlock different safety zones of a machine. It ensures that only one key can be removed at a time, this reduces the risk of unauthorised access or incorrect unlocking of the protected zones.
Learn more about key exchange units

Key plan
A key plan is an organised system for managing keys in a machine park or facility. It includes assigning specific keys to authorised personnel, documenting key positions and managing access rights.

Key transfer systems
Key transfer systems are used to transfer control of machines or equipment between different people or teams. The system consists of specific keys required to access the machine. It is often used in working environments where multiple operators need access to the same machine, but where control of the machine needs to be closely controlled and monitored. The key transfer system ensures that the right people can operate the machine while maintaining responsibility and safety.
Learn more about key exchange units

Keyed alike
Keyed Alike means that multiple padlocks can be opened with the same key. This is useful when there are multiple padlocks that need to be opened with the same key. This can be used when multiple machines or isolation points need to be secured at the same time.
Learn more about safety padlocks

Keyed different
Keyed Different means that each lock has its own unique key and cannot be opened with other keys. This is used when each machine or device needs its own individual safety.
Learn more about safety padlocks

L

Label printers
Label printers are printers used specifically to print labels, tags or stickers containing information about machines, parts, safety regulations, warnings or instructions. Label printers enable users to create clear and highly visible labels that can be attached to machines, tools, safety equipment and other items to improve safety and identification.
Learn more about label printers

Laser scanner
A laser scanner is a safety sensor that uses laser scanning technology to monitor a three-dimensional area and detect objects. Laser scanners are often used as presence detection to prevent people or objects from entering a particular area, or to detect the movement of vehicles or machinery.
Learn more about laser scanners

Light curtains
Light curtains are also known as optical barriers or light barriers. They are electronic safety sensors that create an invisible light pattern between a transmitter and a receiver. They are used to shield hazardous areas and detect when the light pattern is interrupted. Light curtains are designed to prevent persons or objects from accessing dangerous areas or from setting machinery in motion when an object is detected.

Lock out
Lock out is a safety procedure in which the energy supply to a machine, equipment or system is turned off and locked out to prevent it from being inadvertently switched on during maintenance or repair work. This is done to ensure worker safety and prevent accidents.

Locked open
Locked open refers to a state in which a safety system, such as a door lock or shield, is deliberately locked open. This may be necessary in certain situations where continuous access or visibility is required, in which case the safety function is not disabled.

Lockout kit
A lockout kit is a set of tools and equipment used in Lockout-Tagout procedures. A lockout kit usually includes various locking devices, safety padlocks, padlock multipliers, tags and other accessories needed to safely disable and lock out machines and power sources during maintenance or repair work.
Learn more about lockout kits

Lockout stations
Lockout stations are cabinets or boards used to store Lockout-Tagout material in an organised way and make it available to employees. Lockout stations often include hooks, holders and compartments to conveniently store and organise locks, safety padlocks, keys.
Learn more about lockout stations

Lockout-Tagout (LOTO)
A procedural system in which machines and energy sources are switched off, locked and marked to prevent their unintentional activation during maintenance or repair work. LOTO is designed to ensure the safety of workers by protecting them from machines’ hazardous energy sources.
Learn more about Lockout-Tagout

Lockout-Tagout procedures
A Lockout-Tagout procedure are detailed instructions and guidelines for safely locking, tagging and isolating energy sources from machinery or equipment. LOTO procedures are followed during maintenance or repair work to prevent machines from being inadvertently switched on.

Lockout-Tagout-Tryout (LOTOTO)
A procedure used to safely shut down, lockout, tagout and check machines and power sources during maintenance or repair operations. The Tryout behind Lockout-Tagout represents checking that the system has been safely switched off and locked.
Learn more about Lockout-Tagout

M

Machine
A machine is a device that converts mechanical or electrical energy to perform a specific task, such as production, machining or transportation.

Machine directive
The Machinery Directive is a European directive (2006/42/EC) that sets essential health and safety requirements for machinery placed on the market in the European Union. The Machinery Directive aims to ensure the safety and health of persons operating and maintaining machinery.
More on laws and regulations? Read here

Machine guarding
Machine guarding refers to the physical barriers such as fences, panels and doors placed around a machine to restrict access to a hazardous area. The purpose of machine guarding is to protect workers from potential hazards, such as moving parts, cutting tools or falling objects, while still allowing the machine to operate safely.
Learn more about machine guarding

Machine manufacturer
A machine builder is a company or organisation responsible for designing, manufacturing and assembling machines and systems. Machine builders can specialise in different industries and sectors and play a crucial role in ensuring machine safety during the design and construction of machinery.

Machine operator
The machine operator is a person responsible for the safety and proper use of a machine. This person is aware of safety regulations, carries out inspections and maintenance and ensures that the machine complies with the required safety standards and guidelines.

Machine safety
Machinery safety includes technical and organisational measures to ensure that machinery is designed, constructed, installed and used safely. The aim of machine safety is to minimise risks of injury or damage by implementing safety systems, devices and procedures.

MagnaSafe
MagnaSafe is a range of non-contact magnetic safety switches from Mechan Controls. Suitable for use in SIL3, Category 4 and PLe applications.
Learn more about MagnaSafe safety sensors

Magnetic coil
A magnetic coil is an electrical device that creates a magnetic field when current is passed through it. A magnetic coil is often used as part of an electromagnetic circuit, such as a safety interlock system, where the magnetic coil is activated to unlock or lock a latch.

Magnetically encoded
Magnetically coded refers to a safety technology that uses magnetic fields to detect the position and movement of objects. This allows access to machines and areas to be controlled. Magnetically encoded safety sensors use magnetic codes, consisting of magnetic fields with specific patterns, which are detected by magnetic sensors.

Main power
Main power refers to the primary electrical current that flows through a machine or system to enable its normal operation. It includes the power supply to motors, drives and other major electrical components.

Main power switch
The main power switch is a switch used to completely cut off the power supply to a machine. Switching off the main power switch ensures that the machine is completely switched off and isolated from the power supply.

Maintenance
Maintenance includes the regular inspection, cleaning, lubrication and repair of machines to ensure their safe operation and reliability.

Manual restart
A manual restart requires an operator to deliberately perform a restart operation after a machine has been stopped by a safety system. This prevents an unintended automatic restart after a safety intervention.

Masking
Masking is a function of safety light curtain or barrier in which certain parts of the light beam are ignored or switched off to prevent unwanted alarms or reactions. This allows specific areas, for example where moving parts of the machine do not pose a danger to the operator, to be masked.

Master keyed
Master Keyed refers to a key system with a master key. This master key can open multiple locks. Each lock also has its own individual key, but the master key provides access to all locks within the system.

Master Lock
Master Lock is a US manufacturer of Lockout-Tagout products, including safety padlocks, padlock multipliers and various types of interlocks that can be used to perform safe maintenance on machinery.
Read more on Master Lock

Mean Time To Dangerous Failure
Mean Time to Dangerous Failure (MTTFd) is a measure used to assess the reliability of a safety system or component. It indicates the average time between the occurrence of a failure and the dangerous condition of the system or component. MTTFd is often used in determining the Performance Level (PL) according to the ISO 13849 standard for functional safety.

Mechan Controls
Mechan Controls designs and manufactures various machine safety products, including safety sensors, safety switches, mechanical interlocks and safety light curtains.
Read more on Mechan Controls

Mechanical interlocking
A mechanical interlock is a method of interrupting the energy supply to a machine and locking mechanisms such as locks, clamps and pins used to immobilise the moving parts of a machine and prevent it from being started accidentally.

Modular
Modular refers to a modular system where safety components, such as interlocking systems, switches or sensors, are designed as individual modules that can be configured and integrated based on a machine’s specific safety requirements. This modular approach makes modification, expansion and maintenance of the machine safety system easier and more efficient. It provides flexibility when designing and implementing safety solutions.

Monitoring circuit
The electrical circuit responsible for monitoring and controlling the safety functions of a machine, such as safety relays, emergency stop switches and safety sensors.

Motion sensor
A motion sensor detects movement and is used to activate, deactivate or alert machines based on the presence of people nearby.

Motor Control Center (MCC)
A Motor Control Centre is an electrical enclosure that integrates multiple motor starters and motor protection devices to control and protect electric motors.

Multibeam light curtain
A multibeam light curtain is a type of safety sensor consisting of multiple infrared beams extending over a certain distance. It is used to create a protective barrier and detects when one of the beams is interrupted, this may indicate the presence of an object or person in the machine’s danger zone.

N

Negative pressure
A lower pressure than ambient pressure, often created in closed systems, to minimise the risk of leaks or escape of hazardous substances.

Non-contact safety barrier
A safety barrier consisting of a series of sensors and transmitters/receivers that create an invisible protection zone around the hazardous area of a machine, thereby preventing direct contact with the hazardous area.

Non-contact safety switch
A safety switch or safety sensor activated by the proximity of a special key or tag, without physical contact, to immediately disable the machine in case of an emergency.

Normally closed contact (NC)
Normally Closed (NC) contacts are a type of electrical contact that is closed in the idle state and opens when a signal or voltage is applied. This means that electric current flows through the contact when there is no activation.

Normally open contact (NO)
Normally open contacts are a type of electrical contact that is open when at rest and closes when a signal or voltage is applied. This means that no electric current flows through the contact when there is no activation. An NO contact is often used in relays, switches and other electrical devices.

O

Operating buttons
Physical buttons on a control panel or control unit that allow workers to trigger and/or stop specific machine movements or actions.

Operating manual
A document containing detailed instructions and guidelines for the safe operation of a specific machine, including emergency procedures and safety regulations.

Operational risk assessment
The process of identifying and evaluating potential risks and hazards that may occur during the operation of a machine, with the aim of implementing appropriate control measures.

Operator
The operator is the person responsible for operating or maintaining a machine or piece of equipment.

Operator instructions
Written guidelines and procedures specific to a machine or piece of equipment that inform operators about safe operating practices, risks and emergency procedures.

Optical sensor
An optical sensor uses light signals to detect the presence or position of objects, these sensors are often used in safety systems such as light barriers.

Organisational measures
Procedures, rules and safety regulations put in place to promote safe working, such as training programmes, task assignments and work planning

Original Equipment Manufacturer
An Original Equipment Manufacturer (OEM) is a company that produces components, equipment or systems that are used as part of a finished product sold under the brand or name of another manufacturer. For example, in the context of machine safety, an OEM may be the manufacturer of safety components, such as switches, sensors or control modules, used in machines or equipment from other manufacturers.

OSHA (Occupational Safety and Health Administration)
OSHA stands for Occupational Safety and Health Administration. OSHA is a government agency in the United States and is responsible for establishing and enforcing workplace safety and health regulations. OSHA has developed guidelines and regulations to protect workers from potential hazards and risks in the workplace.

OSSD (Output Signal Switching Device)
An OSSD is a solid-state output device used in machine safety systems to activate and deactivate safe stop functions according to strict standards and specifications. It provides reliable signals to other safety components, such as safety relays or controllers, to put machines in a safe state when a safety hazard is detected.

OSSD safety sensors
A safety sensor equipped with an OSSD (Output Signal Switching Device) detects potential hazards or risks in the workplace and generates a safe output signal that can be used to trigger safety measures. Examples of safety measures include; stopping a machine or closing safety doors.
Learn more about safety sensors

Overload
Overloading is a situation where a machine or equipment is subjected to a higher load than it is designed to carry, this can lead to malfunctions or unsafe situations.

P

P&ID (Piping and Instrumentation Diagram)
A P&ID is an engineering drawing that shows the internal operation and process of a system, including piping and instrumentation. In the machine safety world, a P&ID can help identify safety-related components and understand the interaction between different systems.

Performance level (PL)
Performance Level (PL) is a rating system that indicates the performance levels of safety-related parts of machinery according to the ISO 13849-1 standard. The PL level indicates the reliability and effectiveness of a machine’s safety functions, taking into account factors such as the probability of hazardous events and the severity of possible injuries.

Personal protective equipment
Personal protective equipment is the equipment and clothing that individual workers wear or use to protect themselves from potential hazards in the workplace this includes, helmets, safety glasses, hearing protection, safety shoes, gloves, etc.

Personnel access control systems
Safety measures and systems that restrict access to hazardous areas or machinery to authorised personnel. This may include, for example, access control systems, key switches, electronic interlocks or personal safety keys.

Physical barrier
The use of barriers, panels, fences and doors to shield dangerous parts of machinery and prevent unauthorised access to hazardous areas.

Pipe markers
Pipe markers are markers or labels used to identify and mark pipes and tubes in a machine environment. Pipe markers provide information on content, direction of flow, safety regulations or other relevant details to make workers aware of the presence and use of specific pipes.
Learn more about pipe markers

Pneumatic
Pneumatic means using compressed air as an energy source to drive or operate machines, tools or systems. Pneumatic systems are often used in industry because of their reliability, easy operation and safety advantages.

Pneumatic safety
Pneumatic safety is the application of safety measures and practices related to pneumatic systems and equipment. Pneumatic safety includes the use of safety components, such as pressure switches, pressure regulators and safety valves, as well as implementing proper maintenance and inspection routines.

Pneumatic system
A pneumatic system is a system that uses compressed air to drive machinery or equipment or to create movement. It includes components such as compressors, pipes, pneumatic cylinders, valves and pressure regulators.

Pneumatic valve
A pneumatic safety valve is a valve used to regulate the pressure in a pneumatic system and prevent it from reaching a dangerous level. Pneumatic safety valves are designed to open and discharge compressed air when pressure exceeds a preset threshold, ensuring the safety of the system and operators.

Position sensor
A positioning sensor is a sensor used to detect and track the position of an object, such as a moving part of a machine. A positioning sensor can be used to trigger safety functions or to ensure accurate positioning.

Positive air pressure
With positive air pressure, the air pressure within an enclosed space is higher than the ambient air pressure. This is often used in cleanrooms or sensitive environments to keep contaminants out and maintain a safe working environment.

Positive pressure cabinet
A positive pressure cabin is an enclosed space in which the air pressure is higher than the ambient air pressure to prevent the entry of contaminants or hazardous substances. Positive pressure cubicles are often used in situations where a controlled and safe environment is required, such as cleanrooms or laboratories.

Power Control Center
A Power Control Centre is an electrical enclosure that houses power distribution devices and other electrical components to manage power supply and control within a system or building.

Power to Lock
Power to Lock refers to a function in which an electric locking mechanism is activated when power is supplied to the system. This means that the locking of a door, gate or other safety mechanism is activated when electrical power is present. This keeps the door locked and closed until the power supply is interrupted. Power to Lock is often used in situations where it is essential to securely lock an area and prevent unauthorised access.

Power to Unlock
Power to Unlock refers to a function in which an electrical locking mechanism is unlocked when power is supplied to the system. In this case, a door, gate or other safety mechanism is unlocked when electrical power is present. This unlocks the door and allows it to be opened until the power supply is interrupted again. Power to Unlock is often used in emergency situations where rapid evacuation or access to a particular area is required.

Presence detection
A technology used to detect the presence of people or objects near machines, often using laser or radar sensors to identify potential hazards and secure the machine.

Pressure relief valve
A pressure relief valve regulates the pressure in a system by releasing excess pressure, thus reducing the risk of overloading or damage.

Pressure switch
A pressure switch is a switch activated by changes in pressure, this switch is often used to enable monitoring of pressure levels in a system, for example to detect overpressure and activate protective measures.

Preventive maintenance
Preventive maintenance is the regularly scheduled inspection, cleaning, lubrication and repair of machinery to prevent potential malfunctions or unsafe situations before they occur.

Procedure sheet LOTO
A Lockout-Tagout (LOTO) procedure sheet is a document that contains detailed instructions on how to safely lockout and tag machines or equipment during maintenance or repair operations. The procedure sheet describes the steps to be followed to disconnect, lockout and tag the energy supply to the machine to ensure worker safety.

Process interlock
A process interlock is an interlock that locks a machine or system to prevent certain operations or processes from being performed during maintenance, repairs or other critical situations. It ensures that the process is safely stopped and prevents unintended activation or operation.

Process safety assessment
The systematic examination and analysis of processes to identify potential hazards, bottlenecks or inefficiencies. This enables companies to make improvements and increase the safety and efficiency of processes.

Process safety management (PSM)
PSM is a systematic approach to identifying, assessing and controlling hazards in processes involved in the production, storage, handling and transportation of hazardous substances. PSM includes the development and implementation of safety procedures, training, auditing and continuous improvement of processes.

Process safety 
Process safety is the identification, evaluation and control of hazards and risks in industrial processes to ensure that processes are carried out safely. It includes implementing preventive measures, safety devices and emergency procedures.

Process termination
The process of stopping or interrupting a machine or process in the event of an emergency or when a safety hazard is detected. Process shutdown can be triggered by safety sensors, emergency stop switches or other safety devices.

PROFINET
PROFINET is an open standard Ethernet-based communication protocol used for data exchange and control between different devices and systems in an automation environment. PROFINET supports both point-to-point and distributed network architectures and offers flexibility, high speeds and extensive diagnostic capabilities, making it a widely used and established communication standard in industrial automation.

PROFIsafe
PROFIsafe is a safety protocol used in industrial automation to ensure the safety of machines and processes. It is an extension of the PROFINET communication protocol and utilizes redundant and certified safety components to guarantee the reliability and safety of communication.
Read more on PROFIsafe

Programmable Logic Controller
Programmable Logic Controller (PLC) is an industrial computer used to control machines and processes. A PLC is often used to implement safety functions and to monitor safety systems.

Programmable Safety Controller
A PSC is an electronic controller designed specifically for safety applications. A PSC integrates safety functions, such as emergency stop circuits, light curtains and safety doors, and can be programmed to monitor and control safe operation and response to safety situations.

Programmable Safety System
A PSS (Programmable Safety System) is a safety system that uses programmable logic and sensors to implement and monitor safety functions. The PSS can be programmed to respond to specific safety situations and generate emergency stop signals.

Protection cap
A physical barrier used to shield moving parts of machinery to protect workers from direct contact with hazardous parts.

Protection category
A classification system indicating the degree of safety provided by safety components or safety systems, often referred to as category 1,2, 3 or 4, with category 4 having the highest safety integrity. Selecting the right safety category is essential to ensure that safety measures are in line with the risk level of the machine or process.

Protection zone
The safety zone is a defined area around a machine within which certain safety measures apply to ensure the safety of workers.

Protective distance
The protection distance is the distance required between the hazardous area of a machine and the position where workers are located, to prevent direct contact with the hazard.

Proximity sensor
A proximity sensor is a sensor that detects the presence or proximity of objects without physical contact. Proximity sensors are often used in safety systems to monitor the position of workers or objects and to detect movements of machines.

PSV (Pneumatic Safety Valve)
PSV is the Fluidsentry pneumatic safety valve system with electrical monitoring from Fortress Safety. The Fluidsentry PSV system can be retrofitted (retro-fit) into existing pneumatic systems to enable the highest level of safety (Cat. 4, SIL 3, PLe).
Learn more about the PSV pneumatic safety valve

Pushing force
Pushing force is the force exerted when an object is pushed, for example by a machine part. Controlling and limiting pushing force is important to prevent injury or damage.

Q

Quick disconnect
A quick and easy disconnect between cables or connectors. It makes it easy to make and break connections for maintenance or replacement purposes.

R

Range of the machine
The machine’s reach is the area in which the moving parts of a machine are located and where potentially dangerous situations can occur. Defining and delimiting the machine’s reach is important when implementing appropriate safety measures such as machine guards.

Redundancy
Redundancy refers to the use of duplicating or overlapping systems or components to increase the reliability and safety of a system. Redundancy can be applied to sensors, control systems or communication networks to provide a higher level of safety by reducing single points of failure.

Remote-controlled emergency stop
This emergency stop switch can be activated remotely to stop the machine immediately in case of an emergency.

Request to enter
An access request, also known as “request to enter”, is a process by which a person requests permission to enter a certain area or machine. This is often used in machine safety systems where certain areas have restricted access and where a controlled access procedure is required to ensure safety.

Reset button
A reset button is a button or switch that resets a safety function or emergency stop, after it has been activated. The use of a reset button must comply with applicable safety standards.

Residual current
Residual energy is the energy that remains in a system even after the power supply is switched off. It can be potentially dangerous and should therefore be controlled and monitored when carrying out maintenance or repair work on machines.

Residual Current Device (RCD)
Also known as an earth leakage circuit breaker, RCD is a switch used to ensure electrical safety by responding to imbalances between incoming and outgoing current. An RCD disconnects the power supply in case of leakage currents to prevent electric shock.

Residual risks
The residual risk that remains after taking risk-reducing measures. The remaining risk should be controlled and accepted within acceptable limits.

Response time
Response time, also called response time, is the time it takes for a safety component or system to react to a hazardous situation or failure. It is the time that elapses between detecting a hazard and activating the safety measures. Such as interrupting the power supply or stopping the machine. Rapid response is essential for ensuring worker safety and preventing injury.

RFID
Radio Frequency Identification (RFID) is a technology that allows data to be collected and stored wirelessly in tags or labels placed on objects. In machine safety, RFID systems can be used for identification, access control and traceability of materials or persons.

Risk assessment
A risk assessment is the process of analysing and evaluating the risks of a machine or system to identify potential hazards and the level of risk.

Risk identification and evaluation
A risk analysis, also known as Risk Identification and Evaluation (RI&E), is a systematic assessment of potential hazards and risks associated with a machine, process or workplace. It includes identifying hazards, assessing the risks, and taking measures to control or eliminate the risks.

Risk level
Risk level refers to the level of hazard or risk associated with a specific machine, process or situation. The risk level is determined by evaluating various factors, such as the probability of a hazardous incident and the severity of potential damage or injury. It can be measured by criteria such as the frequency and duration of exposure to the risk, the potential impact on workers’ health and safety, and the availability and effectiveness of safety measures. By assessing the level of risk, appropriate measures can be taken to control and reduce risks to acceptable levels. This may include implementing safety provisions, training employees, adjusting work processes and following applicable safety standards.

Risk reduction
Is the taking of measures to reduce or eliminate the risks of a machine or system through technical, organisational or procedural modifications.

Robustness
The ability of a machine or safety system to continue to function reliably even under adverse conditions, such as vibration, shock or interference.

S

Safe door contact
A safe door contact is a sensor or switch used to monitor the status of a safety door. It detects whether the door is open or closed and can control machine operation or access to hazardous areas. It ensures that the machine stops or cannot be started if the door is open.

Safety contacts
Safety contacts are switches or sensors used in machine safety applications to detect the presence or movement of persons. Safety contacts are used to stop machines or activate safety measures when dangerous situations are detected.

Safety controller
An electronic control unit specifically designed to control safety-related functions in machines or systems. Safety controllers monitor and control safety devices and ensure that the machine meets the required safety standards.

Safety equipment/fixture
A device, system or component designed and installed to ensure the safety of persons in the vicinity of machinery and equipment. Examples of safety devices include emergency stop buttons, light curtains, safety door switches and guards.

Safety expert
A safety expert is a workplace safety and health professional. In the context of machine safety, a safety expert is responsible for assessing risks, designing safety measures and implementing safety guidelines to ensure worker safety and compliance with safety standards.

Safety Integrity Level (SIL)
SIL is a classification system that indicates the reliability of safety-related systems and instrumentation according to standards IEC 61508 and IEC 61511. SIL levels indicate the ability of a system to detect, prevent or control dangerous situations, with the aim of reducing the risks of injury or damage.

Safety interlock
A safety interlock, also known as a safety interlock, is a safety mechanism used to control access to hazardous areas or the starting of machinery. Safety interlocks detect whether predetermined safety conditions are met before a certain action can take place, thereby reducing the risk of injury.

Safety key
A safety key is a special key used to restrict access to dangerous areas of a machine. This key is used in conjunction with locking systems to ensure that only authorised personnel have access to certain parts of the machine.

Safety key transfer system
Key transfer systems are used to transfer control of machines or equipment between different people or teams. The system consists of specific keys required to access the machine. It is often used in working environments where multiple operators need access to the same machine, but where control of the machine needs to be closely controlled and monitored. The key transfer system ensures that the right people can operate the machine while maintaining responsibility and safety.

Safety manager
Person within an organisation responsible for safety measures and procedures, including machine safety.

Safety mechanism
A mechanism designed to ensure the safety of a machine, such as an interlock, emergency stop switch or safety sensor.

Safety outputs
Safety outputs are electrical outputs or circuits designed to respond specifically to safety-related events or to trigger safety functions. They can be used to control safety devices, such as emergency stop switches or safety door switches, and monitor critical safety functions.

Safety PLC
A safety PLC (Programmable Logic Controller) is a special type of programmable logic controller designed and programmed to monitor and control safety functions in machines and systems. It provides advanced safety features and complies with strict safety standards to ensure the safe operation of machines. A safety PLC receives signals from safety sensors and makes decisions based on predefined safety logic. Among other things, it can be used to monitor emergency stop switches, safety doors, light curtains and other safety equipment. In case of an emergency, the safety PLC can react quickly and reliably by shutting down the machine or activating other appropriate safety measures.

Safety relay
A safety relay is a specific type of relay used to control and monitor safety circuits. Safety relays are used to ensure quick and reliable shutdown of machines in case of emergency shutdown or other safety incidents.

Safety zones (1, 2, 3, 4)
A classification system indicating the degree of safety provided by safety components or safety systems, often referred to as category 1,2, 3 or 4, with category 4 having the highest safety integrity. Selecting the right safety category is essential to ensure that safety measures are in line with the risk level of the machine or process.

Screw fuse
A screw fuse, also known as a wire fuse, is a type of fuse used to protect electrical circuits from overloads or short circuits. It consists of a tube-shaped ceramic body with a metal wire that melts and interrupts when the current is too high, interrupting the power supply to the circuit. A screw fuse can be replaced with a new fuse after it has been triggered.

Selector switch
A selector switch is a switch used to manually switch between different operating modes or functions. A selector switch can be used to select the operating mode of a machine, such as manual operation, automatic mode or maintenance mode.

Shadow boards
Shadow boards are visual aids for lockout tagout (LOTO) procedures. They provide organised storage of safety padlocks, interlocks and safety tags. Using shapes or outlines, the board indicates where each device should be stored. This helps maintain traceability and visibility, improving compliance with procedures and workplace safety.
Read more on shadow boards

Signal lamp
A signal lamp, also known as a signalling lamp or indicator lamp, is a visual indicator used to indicate the status or condition of a machine, process or system. The LEDs in a signal lamp can have different colours, such as green, red or yellow, the different colours being used to convey different meanings or warnings. Signal lights are often used in machine safety applications to indicate whether a machine is operating, malfunctioning or signalling a hazardous situation.

SISTEMA library
SISTEMA stands for “Safety Integrity Software Tool for the Evaluation of Machine Applications”. It is a software tool used to calculate and evaluate the safety performance of safety systems according to international standards. The SISTEMA library contains data on various safety components and helps assess the reliability of safety functions.

Status LED
A status LED is a light-emitting diode used to indicate the status of a device, component or system. A status LED is often used in machine safety applications to visually display operational status, fault conditions or other important information. A status LED can have different colours, such as green, red or yellow, to convey predetermined meanings.

Sufficiently educated person
Employee with basic knowledge and training to perform specific tasks related to safety and machine operation under the supervision of a qualified person.

Switching distance
Switching distance refers to the distance at which a sensor or switch responds when an object or person comes within the detection range. It is the minimum distance required to trigger a switching action.

System implementation
Integrating safety systems means seamlessly combining different safety components and systems within a machine or plant. This ensures coordinated and effective safety functionality.

T

Technical Installation Company
A TIP (Technical Installation Company) company is a company that specialises in designing, installing and maintaining technical installations, including machine safety equipment. TIP companies have the expertise and knowledge to ensure safety aspects in machinery and equipment.

Three-position rotary switch
A 3 position switch is a switch with three possible positions: on, off and locked. It is often used in machine safety applications to control different modes of operation, such as normal operation, maintenance mode and locked mode for service or repairs.

Trapped key
A mechanism used to ensure a safe sequence of work on machinery and equipment. A trapped key system prevents certain operations from being performed unless the key is used in the correct sequence, thus reducing potential hazards.

Troax
Steel mesh panels for machine guarding have been produced by Troax for 60 years. The largest provider of modular safety fence systems globally now is Troax.
The lightweight yet incredibly robust mesh panels can be created or equipped with accessories to make them appropriate for nearly any purpose. High criteria for safety are combined with controlled access for permitted people in today’s industrial environments with modern processes. The Troax mesh panels are a part of a well-designed modular system that can be assembled using standard components to fit any space.
Read more on Troax

Turn-off delay
The lag time, also known as the switch-off delay, is the time it takes to stop a machine completely, after activating the stop signal. It is an important parameter to ensure that moving parts have come to a safe stop before maintenance work is carried out, for example.

TüV-certified
TüV certified means that a product, system or process has been tested and meets the safety standards and requirements set by TüV, an independent certification body. The TüV certificate confirms that the product or system has been found to be safe and reliable.

Two-hand control
Two hands operation is a safety measure that requires both hands of an operator to be used simultaneously to perform a certain action or activation. This is often used on dangerous machines to prevent an operator from accidentally performing a dangerous action.

Type 2 light curtain
A Type 2 light curtain is a type of safety sensor used for low- to moderate-risk applications. It provides object detection and can stop the machine or secure the danger zone when an interruption of the light beam is detected.

Type 4 light curtain
A Type 4 light curtain is a type of safety sensor used to monitor and secure hazardous areas or zones. It provides protection through infrared rays and has the highest safety category according to safety standards.

V

Valve (lockout)
A valve latch is a mechanism or locking system that can be applied to valves (valves). This prevents unauthorised operation and ensures the safety of the machine and workers.

X

W

Wiring diagram
A wiring diagram is a diagram that shows the electrical wiring and connections between electrical components in a machine or system. It provides detailed information on how electrical current flows and how components are connected.

Work permit
A work permit is a document used to carry out planned work on a machine or plant safely. It contains information about the tasks to be performed, the safety measures required and any special instructions to reduce risks.

Y

Z

ZPM (Zero pressure monitor)
Through a single or dual channel, the zero pressure monitoring, or ZPM, offers input on the isolation condition of a hazardous energy system. To increase reliability and stop a single failure or malfunction from taking down the system, dual channels are utilised.