Glossary · Protective devices and interlocks
Muting
German: Muting
In machine safety, muting is the temporary automatic suspension of a protective function under specified, monitored conditions, typically to let material pass through a light curtain while people are still detected.
- Machine safety
- Risk assessment
In one sentence
Muting temporarily suspends a light curtain so pallets can pass; muting sensors must tell material from people, and the suspension must end automatically.
Example
At the outfeed of a pallet wrapper, two pairs of muting sensors detect a pallet in the correct sequence and suspend the light curtain only while the pallet passes.
How it applies
- Machine safety: Muting is only acceptable if the muting conditions reliably distinguish material from a person, for example through sensor arrangement, sequence and timing. The muting function itself must meet the same safety requirements as the protective function it suspends.
- Design: Limit muting in time, end it as soon as the material has passed, and prevent a person from entering alongside or on top of the load.
- Evidence: Muting is a frequent source of accidents and bypass behavior, for example sensors blocked with tape. Validation should test misuse scenarios, not just the intended flow.
- Technical documentation: Describe muting conditions, indicator lamps and override functions, and prohibit changes to muting sensor positions.
Muting vs. blanking
Muting suspends the whole protective function temporarily. Blanking ignores defined parts of the field while the rest stays active.