How can one tell if the imager needs calibration?

Most manufacturers suggest that an IR camera be serviced with a calibration check annually, like many other instruments. The checklist below outlines the FLIR annual service program. 

FLIR 14 POINT INSPECTION & CALIBRATION PROGRAM

1. Perform a complete operational check
2. Fusion calibration and laser alignment, when applicable
3. Verify all internal cable and PCB connections
4. Clean viewfinder and check optics
5. Upgrade internal camera software to latest revisions
6. Perform minor repairs
7. Verify and/or re-equalize as needed each temperature range for image uniformity
8. Verify standard lens calibration (others or special engineered lenses, optional)
9. Verify ambient temperature compensation as needed
10. Re-calibration to ensure it meets factory specification
11. Calibrate temperature ranges up to +1,500°C, when applicable
12. Perform quality approved acceptance test procedure
13. Provide calibration label with next due date
14. Provide calibration certificate (optional, extended calibration certificate with measured values)

 Here is a quick way you can check your camera calibration in the field:

1. Measure the temperature of a MELTING ice cube. The reading should be 0 C +/- 2 C.
2. Measure the temperature of boiling water (if you are near sea level). Reading should be 100 C +/- 2 C