Process quantity measurement device

A process quantity measurement device for measuring a plurality of types of process quantity related to compressed gas, the process quantity measurement device comprising:

• a pipe in which compressed gas pass through;
• a pressure sensor configures to generate a pressure signal corresponding to a pressure of the compressed gas passing through the pipe;
• a thermo-hygrometer configured to measure a temperature and a humidity of the compressed gas passing through the pipe;
• a user interface configured to receive an input of a pressure of the compressed gas in the supply source;
• a dew point estimation unit that estimates a dew point in the supply source based on the pressure signal generated by the pressure sensor, the temperature and the humidity measured by the thermo-hygrometer, and the pressure of the compressed gas in the supply source received via the user interface;
• and
• a display unit that displays the dew point estimated by the dew point estimation unit.