Two calibrated sensors can read different temperatures depending on their response times.
Below are some reasons why a temperature difference may exist.
Overview
Microclimates within fridges and freezers can account for a ±10ºC difference based on the sensor location. You can learn more in a government report published by NIST.
SmartSense sensors are programmed to take temperature readings at specific intervals (5 minutes, 15 minutes, 30 minutes, etc.). When compared to a second thermometer, the time a temperature reading was taken may cause a disparity.
SmartSense sensors measure temperature with an accuracy of ±0.5ºC. All sensors leaving the manufacturer's factory are compared against a NIST traceable reference.
This is available upon request. This letter is not a calibration certificate and cannot be used in place of a calibration certificate.
How to determine sensor accuracy
The best way to guarantee the accuracy of a sensor is to purchase a SmartSense calibration service. The SmartSense Support Team can assist you.
The sensor will ship to an accredited laboratory to compare it to a NIST traceable reference thermometer.
The calibration certificate generates the recorded temperature from your sensor and the reference temperature.
Ensure the sensors are recording information using the correct unit of measurement (Fahrenheit or Celsius).