[18p-231A-1~14] 1.5 Instrumentation, measurement and Metrology

△ [18p-231A-3] A Study on Automation for the Two-Pressure Humidity Generator

〇Naoya Ishiwata¹, Tamio Niwa¹, Hisashi Abe¹ (1.National Metrology Institute of Japan (NMIJ), AIST)

Keywords:high humidity, humidity generator, automated control

Humidity standard, which is a gas with known humidity, is needed for testing performance of hygrometers used in many industrial fields. In this study, the humidity generator for high humidity standard was automated in order to improve accuracy of generated dew point and efficiency of calibration service. The dew point of humid air generated by the instrument depends on temperature of saturation bath, air pressure in the generator, and atmospheric pressure. Therefore, fluctuations of either bath temperature or atmospheric pressure make accuracy of generated dew point worse. In order to address this problem, we developed an automated system for controlling dew point by regulating the air pressure in the generator. Using this system, we were successful in suppressing the dew-point fluctuation.