Abstract: A pressure measuring system for a refrigeration system, such as a refrigeration system used in a commercial air conditioning system, comprises a converter (42) for converting a pressure being measured into a digital signal representing the measured pressure and a processor (54) for calculating a corresponding boiling point temperature for a selected refrigerant at the measured temperature. The system also includes a selector for selectively inputting the boiling point temperature-pressure relationship or coefficient of a selected refrigerant into the processor, as well as a display (60) for displaying the measured pressure and the calculated boiling point temperature.