R-Pro › Field cases › Transport refrigeration

Data Logger / Temperature Recorder Inaccuracy

Likely causes

Temperature sensor (Pt100/NTC) aging or overdue calibration

Check: Compare against NIST-traceable reference thermometer — measure at 3 points (front/middle/rear); if deviation >2°C, calibrate or replace

What to do: 2-point calibration: ice bath (0°C) and dry ice (-78.5°C) → replace sensor if calibration impossible → maintain calibration interval within 1 year

Poor sensor probe placement — installed directly in front of evaporator discharge

Check: Check sensor installation position: minimum 1m from evaporator discharge, no direct cargo contact

What to do: Relocate sensor to appropriate position (1m+ from evaporator discharge) → install protective case to prevent direct cargo contact → re-verify temperature deviation after relocation

Data logger internal battery discharged — timestamp error

Check: Check data logger clock accuracy — if more than 1 hour off from reference time, suspect battery discharge

What to do: Replace data logger battery → configure NTP or GPS-based time synchronization → check if ATP certification re-issuance is required

Field tip

Data loggers for legally required transport temperature records must be calibrated within 1 year — keep calibration history in the vehicle at all times for use as legal evidence.

All 565 cases work offline in R-Pro, with error codes for 62 brands and P-T data for 108 refrigerants.

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