[13p-S401-1~11] 1.5 Instrumentation, measurement and Metrology

△ [13p-S401-6] Improving the Responsiveness of the Active Dew-Point Control in the Two-Pressure Humidity Generator

〇Naoya Ishiwata¹, Hisashi Abe¹ (1.AIST)

Keywords:high humidity, humidity generator, dew-point control

Humidity standard, which is a gas with known humidity, is needed for testing performance of hygrometers used in many industrial fields such as automotive and food. In this study, we developed an active dew-point control system for a primary humidity generator of high humidity in order to improve accuracy of generated dew points and efficiency of calibration service. Using this system, we have already succeeded in suppressing dew-point falls in generating a gas with a high dew point and dew-point oscillations under large temperature oscillations in the generator. However, since gas volume in the generator is large in order to achieve good pressure stability, the responsiveness of the dew-point control system under rapid dew point changes and fluctuations was insufficient. To address this challenge, we developed an additional pressure control method with the expansion valve between the saturator and the test chamber and by using it, we were successful in improving the responsiveness of the dew-point control system.