Calibration of Temperature and Pressure Sensors for DAQ System in Air Conditioning Test Rig

This work has been done to develop a data acquisition system for a computerized test rig which had gone defective. A conventional air conditioning test rig with the same specifications of the computerized one was selected and the sensors were calibrated. In order to automate data acquisition system, the sensors’ output which gives raw data has to be converted to values that can be understood and used in calculations. Both test rigs—one conventional and another computer interfaced with one, having the same capacity and compressors are run in the same environment. The sensor data from computer interfaced test rig is collected in ESP8266 Node MCU board and raw data of temperature is compared with readings obtained on a digital thermometer and the raw data of pressure is compared with the analog pressure gauges fitted on conventional test rig. An equation is derived to represent the raw data in terms of usable values for calculation. The result shows that calibration has been successful. It is concluded that by this calibration process any system can be modified and upgraded to computer interfaced one.