[20p-E313-1~17] 1.5 Instrumentation, measurement and Metrology

△ [20p-E313-3] Active Dew-Point Control of the Two-Pressure Humidity Generator

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

Keywords:humidity standard, humidity generation, active 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 fluctuations in atmospheric pressure. However, when a gas with a low dew point is generated, the performance of the dew-point control system under large temperature oscillations in the generator was insufficient. To address this challenge, we assessed a new temperature measurement system and by using it, we were successful in improving the performance of the dew-point control system.