High Accuracy Acoustic Relative Humidity Measurement in Duct Flow with Air

Sensors

Wilhelm van Schaik²  Mart Grooten¹  Twan Wernaart¹ 

[1] Process Technology, Department of Mechanical Engineering, Eindhoven University of Technology, Den Dolech 2, 5600 MB, Eindhoven, The Netherlands;Van Schaik Innovation Handling B.V., Glaslaan 2, Building SWA 1.032, 5616 LW, Eindhoven, The Netherlands, E-Mail:

关键词: acoustics;    relative humidity;    humid air flow;   

DOI  :  10.3390/s100807421

来源: mdpi

【 摘 要 】

An acoustic relative humidity sensor for air-steam mixtures in duct flow is designed and tested. Theory, construction, calibration, considerations on dynamic response and results are presented. The measurement device is capable of measuring line averaged values of gas velocity, temperature and relative humidity (RH) instantaneously, by applying two ultrasonic transducers and an array of four temperature sensors. Measurement ranges are: gas velocity of 0–12 m/s with an error of ±0.13 m/s, temperature 0–100 °C with an error of ±0.07 °C and relative humidity 0–100% with accuracy better than 2 % RH above 50 °C. Main advantage over conventional humidity sensors is the high sensitivity at high RH at temperatures exceeding 50 °C, with accuracy increasing with increasing temperature. The sensors are non-intrusive and resist highly humid environments.

【 授权许可】

CC BY   
© 2010 by the authors; licensee MDPI, Basel, Switzerland.