How is superheat measured in a refrigeration system?

Superheat in a refrigeration system refers to the temperature of the refrigerant vapor above its saturation temperature at a given pressure. To accurately measure superheat, it's essential to compare the low side saturation temperature—determined by the refrigerant pressure in the evaporator—with the temperature of the refrigerant vapor in the suction line.

By measuring the suction line temperature and subtracting the corresponding saturation temperature at that pressure, you can determine how much the vapor has been heated beyond its boiling point. This process is crucial because it ensures that the refrigerant is entirely vapor before entering the compressor, helping to prevent damage and ensuring efficient operation.

Thus, measuring the superheat this way provides vital diagnostic information about the performance and operation of the refrigeration system, helping technicians identify potential issues such as low refrigerant levels or a malfunctioning expansion device.