1 - Install a low pressure gauge at the outlet of the evaporator, convert the pressure read on the gauge to a temperature called the evaporation temperature, for this a table or pressure scale x temperature in the scale equivalent to the type of refrigerant being used must be used used in the installation of the refrigeration system.
2 - Using a reliable thermometer, measure the suction temperature near the sensor bulb of the thermostatic expansion valve.
3 - The value of the superheat will be the same: suction temperature (obtained through the thermometer) - evaporation temperature (obtained through suction pressure converted to saturated temperature).
Generally the factory setting of thermostatic expansion valves in the vast majority and from 3 to 7 K.
