Guide · Calibration
Temperature sensor calibration: keep every probe in date without a spreadsheet.
An uncalibrated sensor makes every reading it took questionable. Most lapses are not technical failures; someone forgot a due date.
Why calibration lapses happen
- Due dates live in a spreadsheet one person maintains.
- Sensors are added or swapped without updating the list.
- Calibration vendors need lead time that nobody planned.
- Overdue sensors keep reporting, so nobody notices.
What a calibration register should hold
| Field | Example |
|---|---|
| Sensor ID and location | Freezer 3, upper shelf probe |
| Last calibration date | Date of the certificate |
| Next due date | From your calibration interval |
| Certificate reference | Linked document |
| Status | In date, due soon, overdue |
A simple process that holds
- Build one register of every sensor in use, linked to its unit.
- Set the interval your quality system requires for each sensor type.
- Send reminders well before the due date, then again closer to it.
- Raise an alarm when a sensor becomes overdue, not just a note.
- Attach the certificate when calibration is done and reset the due date.
- Review the register monthly with QA.
How ColdWatch does it
ColdWatch monitors freezers from −80 °C to cold rooms at 2–8 °C, plus product probes and door contacts, on the sensors you already have, over BACnet/IP or Modbus TCP. It raises five alarm types (high, low, rate of change, comms gap and sensor failure) and escalates by screen, email, SMS and push until someone acknowledges with a mandatory comment. AI projects drift forward to say which unit is likely to breach next and roughly when. Excursions go into a register with duration, peak, shift and severity; calibration due dates are tracked with reminders at 30, 15 and 7 days; and every reading, alarm and action is kept in an append-only ALCOA+ audit trail for five years, with IQ/OQ/PQ documents delivered as part of go-live.
Questions
How do I track temperature sensor calibration?
Keep one register of every sensor with last and next due dates and certificates, send reminders before each due date, and alarm when a sensor goes overdue.
How often should temperature sensors be calibrated?
At the interval set by your quality system and the sensor maker; many sites use a yearly interval, but follow your own SOP.
See it on your own data. ColdWatch — Every freezer, every minute. Book a 30-minute working session with an engineer.