Glossary · Safe work, maintenance and competence
Inspection interval
In maintenance and safety management, an inspection interval is the specified time, usage or condition threshold between inspections of a machine, component or protective measure.
- Machine safety
- Maintenance
In one sentence
An inspection interval sets how often, by time, usage or condition, a machine or safeguard must be checked, and it needs a stated rationale.
Example
The manufacturer of a palletizer specifies inspection of the guard door interlocks every 1,000 operating hours or every three months, whichever comes first, and of the lifting chains weekly.
How it applies
- Machine safety: Protective devices, interlocks and guard integrity degrade in use. The inspection interval must be short enough to find a failure before it matters, and for some safety functions it follows from the design assumptions, such as a proof test interval.
- Technical documentation: State the interval unambiguously: unit, trigger and “whichever comes first” where several apply. Say what to inspect and what the acceptance criteria are.
- Integrated systems: Where usage counters or condition data trigger inspections, the data source becomes safety-relevant. Stale or missing data must not silently extend the interval.
- Evidence: Inspection records against the interval show that periodic verification is happening.
Inspection interval vs. maintenance interval
An inspection checks condition; it may lead to maintenance. A maintenance interval schedules the work itself, such as replacing or lubricating parts.