Why doesn’t my digital thermometer read the same as the DishTemp?

Answer (from ThermoWorks)

In the past, one of the most common ways to document the dishware temperature has been with a waterproof pocket digital thermometer. This has always been problematic; all pocket digitals thermometers have the sensor lodged in the tip of the probe. Because of this design, pocket digitals are susceptible to inaccurate readings because they only read the water temperature measured at its tip which leads to an increased number of false positive readings. Pocket digitals often give a temperature of the water, but not the surface temp that is required by code.