Glossary · Guards and machine motion
Tamper resistance
In machine safety, tamper resistance means the design characteristics that make defeat or unauthorized adjustment of a protective measure difficult, such as coded actuators, concealed mounting or tool-secured settings.
- Machine safety
- Human factors
In one sentence
Tamper resistance makes guards and interlocks hard to defeat, but it works best together with designs that remove people's motivation to bypass them.
Example
A packaging machine uses RFID-coded interlock switches mounted behind the door frame, so that a spare actuator or a magnet cannot be used to fake a closed door.
Explained in context
Context cards connect this term with others to answer one question. Also in British English and German.
How it applies
- Machine safety: ISO 14119 requires designers to minimize the possibility of defeating interlocking devices, for example by choosing coded actuators, concealed or protected mounting, and monitoring. The appropriate measures depend on how easily a device can be defeated.
- Human factors: Tamper resistance treats the symptom. Bypass behavior usually starts when a safeguard gets in the way of a task. Ask why people would defeat it and provide a safe mode for that task.
- Cybersecurity: Parameters of programmable protective devices, such as scanner fields or muting settings, also need protection against unauthorized change, for example by passwords and change logs.
- Technical documentation: State in the instructions that defeating or modifying safeguards is prohibited, and describe the approved procedure for tasks that need access.
Tamper resistance vs. guard integrity
Tamper resistance protects against deliberate defeat. Guard integrity is about withstanding loads, wear and the environment.