Over time, with continued use, as a result of drops and other kitchen mishaps a thermometer can become less accurate and require recalibration to determine how far off the mark it really is.
Ice Baths Articles ( Results)
Thermal Secrets to Creating a Properly Made Ice Bath
The easiest way to test the accuracy of any thermometer is in a properly made ice bath. If you do this carefully, your ice bath will be 32.0°F within ±0.1°F.
The Truth About Ice Baths: Five Secrets Revealed
Learn the five secrets and you will understand ice baths like never before.