Few manufacturers have given any thought to providing the user a convenient means to monitor internal temperature conditions of a refrigerator or freezer from the outside. Water testing laboratories require constant monitoring of refrigerators and incubators for compliance to standard operations. The Hanna Instruments HI 147 Check-fridge thermometer Checkfridge is the ideal thermometer for accurate, reliable internal temperature readings.
How do you know when the reading on the thermometer is correct? An ice point or slurry could be made. Even then there could be several degrees difference in the real verus theoretical temperatures. With the Hanna Instruments HI147, there is no need to waste time preparing and ice bath for making these tests. It's unique CAL CHECK feature can simulate it. Conveniently located on the face of the thermometer is a TEST switch. Engage the switch and the Hanna Instruments HI 147 performs an internal calibration check. In only a few seconds, you see the results on the large LCD. Return the switch to the READ position and the Hanna Instruments HI-147 returns to its normal measuring status.