Development of Psychrometric Measurement Equipment and Online Data Logging

The psychrometric properties of air are useful in a variety of applications such as food processing, agriculture, livestock, heating ventilation and air conditioning (HVAC) and combustion system. The psychrometer, barometer, and psychrometric chart are often used to determine the air psychrometric qualities, which take time to analyze. The psychrometric data logging developed in this study consists of microcontroller board (esp32), temperature and humidity sensor (SHT 31), and atmospheric pressure sensor (BMP 180). The psychrometric properties of air derived from psychrometric data logging comprise of dry bulb temperature, wet bulb temperature, relative humidity, atmospheric pressure, dew point temperature, saturation vapor pressure, vapor pressure, mixing ratio, specific volume and enthalpy uploaded to google sheet via wireless fidelity (wi-fi). The psychrometric properties of air as determined by psychrometric data recording were compared with Testo 625, psychrometer, and barometer; the inaccuracies ranged from -1.87% to 2.82%.