Next Article in Journal
Laser Induced Breakdown Spectroscopy for Elemental Analysis in Environmental, Cultural Heritage and Space Applications: A Review of Methods and Results
Next Article in Special Issue
T-Patterns Revisited: Mining for Temporal Patterns in Sensor Data
Previous Article in Journal
Use of Sensors in the Treatment and Follow-up of Patients with Diabetes Mellitus
Previous Article in Special Issue
Mobile Sensor Networks for Inspection Tasks in Harsh Industrial Environments
Article Menu

Export Article

Open AccessArticle

High Accuracy Acoustic Relative Humidity Measurement inDuct Flow with Air

Van Schaik Innovation Handling B.V., Glaslaan 2, Building SWA 1.032, 5616 LW, Eindhoven, The Netherlands
Process Technology, Department of Mechanical Engineering, Eindhoven University of Technology, Den Dolech 2, 5600 MB, Eindhoven, The Netherlands
Author to whom correspondence should be addressed.
Sensors 2010, 10(8), 7421-7433;
Received: 20 June 2010 / Revised: 15 July 2010 / Accepted: 30 July 2010 / Published: 9 August 2010
(This article belongs to the Special Issue State-of-the-Art Sensors Technology in The Netherlands)
PDF [909 KB, uploaded 21 June 2014]


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. View Full-Text
Keywords: acoustics; relative humidity; humid air flow acoustics; relative humidity; humid air flow

Graphical abstract

This is an open access article distributed under the Creative Commons Attribution License (CC BY 3.0).

Share & Cite This Article

MDPI and ACS Style

Schaik, W.; Grooten, M.; Wernaart, T.; Geld, C. High Accuracy Acoustic Relative Humidity Measurement inDuct Flow with Air. Sensors 2010, 10, 7421-7433.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Sensors EISSN 1424-8220 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top