The HI762070C Calibration Check Key at 70℃ is designed to check the accuracy of your thermistor thermometer. This check key is compatible with any of Hanna’s thermistor thermometers that use the HI762 series of probes. By simply connecting the calibration key to the probe input, the user can quickly determine if the meter needs to be recalibrated. If the reading on the display differs more than 0.4℃ from the key rated value, the thermometer should be recalibrated at our technical service center. For periodic verification of your thermometer’s calibration, it is recommended to check at least two calibration points. The value of the calibration check keys should be chosen based on the expected temperature of the sample.