Glossary · Verification and validation
Periodic verification
Also known as: periodic inspection, periodic check
In machine safety and functional safety, periodic verification is the scheduled confirmation that a protective measure remains effective in operation. It covers guards, protective devices and safety functions whose performance can degrade over time.
- Verification
- Functional safety
In one sentence
Periodic verification confirms at planned intervals that guards, protective devices and safety functions still work as intended.
Example
Each month, the maintenance team of a stamping line measures the stopping time of each press, tests the light curtains with a test rod and inspects the fixed guards for damage.
How it applies
- Machine safety: Protective measures wear and get bypassed. Periodic verification detects loss of effectiveness before an accident does. Typical items are guard integrity, stopping time, interlock function and sensor alignment.
- Technical documentation: The manufacturer states what to check, how and how often in the maintenance manual. The user sets the actual inspection interval based on this and on local use.
- Evidence: Record each verification with date, results, deviations and corrective actions. Regulators and insurers ask for these records after incidents.
- Functional safety: Some safety calculations assume tests at defined intervals. If the periodic verification is not performed, the claimed level may not be reached.
Periodic verification vs. proof test
Periodic verification is the broader term and includes visual inspections and simple checks. A proof test is a specific periodic test designed to reveal hidden dangerous failures of a safety function.