{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T04:38:54Z","timestamp":1760243934590,"version":"build-2065373602"},"reference-count":14,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2010,8,9]],"date-time":"2010-08-09T00:00:00Z","timestamp":1281312000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>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\u201312 m\/s with an error of \u00b10.13 m\/s, temperature 0\u2013100 \u00b0C with an error of \u00b10.07 \u00b0C and relative humidity 0\u2013100% with accuracy better than 2 % RH above 50 \u00b0C. Main advantage over conventional humidity sensors is the high sensitivity at high RH at temperatures exceeding 50 \u00b0C, with accuracy increasing with increasing temperature. The sensors are non-intrusive and resist highly humid environments.<\/jats:p>","DOI":"10.3390\/s100807421","type":"journal-article","created":{"date-parts":[[2010,8,9]],"date-time":"2010-08-09T11:13:47Z","timestamp":1281352427000},"page":"7421-7433","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":24,"title":["High Accuracy Acoustic Relative Humidity Measurement inDuct Flow with Air"],"prefix":"10.3390","volume":"10","author":[{"given":"Wilhelm van","family":"Schaik","sequence":"first","affiliation":[{"name":"Van Schaik Innovation Handling B.V., Glaslaan 2, Building SWA 1.032, 5616 LW, Eindhoven, The Netherlands"}]},{"given":"Mart","family":"Grooten","sequence":"additional","affiliation":[{"name":"Process Technology, Department of Mechanical Engineering, Eindhoven University of Technology, Den Dolech 2, 5600 MB, Eindhoven, The Netherlands"}]},{"given":"Twan","family":"Wernaart","sequence":"additional","affiliation":[{"name":"Process Technology, Department of Mechanical Engineering, Eindhoven University of Technology, Den Dolech 2, 5600 MB, Eindhoven, The Netherlands"}]},{"given":"Cees van der","family":"Geld","sequence":"additional","affiliation":[{"name":"Process Technology, Department of Mechanical Engineering, Eindhoven University of Technology, Den Dolech 2, 5600 MB, Eindhoven, The Netherlands"}]}],"member":"1968","published-online":{"date-parts":[[2010,8,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Wernecke, R (2003). 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V90;."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"724","DOI":"10.1121\/1.1369103","article-title":"On the theory of acoustic flow measurement","volume":"110","author":"Wendoloski","year":"2001","journal-title":"J. Acoust. Soc. Am"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1016\/j.flowmeasinst.2007.09.004","article-title":"Nonlinearities in ultrasonic flow measurement","volume":"19","author":"Willatzen","year":"2008","journal-title":"Flow Meas. Instrum"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1016\/S0955-5986(96)00019-2","article-title":"Optical flow field investigations for design improvements of an ultrasonic gas meter","volume":"7","author":"Melling","year":"1996","journal-title":"Flow Meas. 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