Qualifying a temperature monitoring system
Installation checks, functional tests including alarm and failure modes, and a performance period under routine use — plus the software validation that sits underneath.
A monitoring system is both a measuring system and a computerised system, so its qualification draws on both ISO/IEC 17025-style metrological evidence and Annex 11-style software controls.
OQ tests that are often missed
- Sensor removed or failed: does the system alarm, and does the record show the gap?
- Gateway or network down for an hour: are data back-filled, in order, without duplicates?
- Clock changes and time zones: are timestamps consistent?
- User without rights attempts to change an alarm limit: is it refused and logged?
- Alarm acknowledged but condition persists: does it re-alarm or escalate?
The PQ period ends with a report confirming the system is fit for use and defining the routine review, calibration and periodic-review arrangements.
Frequently asked questions
- How long should PQ run?
- Long enough to see routine operation including door traffic, defrost cycles and at least one alarm event — commonly two to four weeks for storage systems.
References
- [1]WHO Technical Supplement 16 to TRS 961 Annex 9: Environmental temperature monitoring systems for fixed storage areas
- [2]EudraLex Volume 4, Annex 11: Computerised Systems
- [3]ISO/IEC 17025:2017 — General requirements for the competence of testing and calibration laboratories
General technical guidance written against the cited sources. It is not regulatory or legal advice and does not replace the applicable standard, guideline or a qualified reviewer's judgement.
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