A High Temperature Capacitive Humidity Sensor Based on Mesoporous Silica

Capacitive sensors are the most commonly used devices for the detection of humidity because they are inexpensive and the detection mechanism is very specific for humidity. However, especially for industrial processes, there is a lack of dielectrics that are stable at high temperature (>200 °C...

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Bibliographic Details
Main Authors: Michael Tiemann, Jan Roggenbuck, Sören Krotzky, Claus-Dieter Kohl, Tilman Sauerwald, Alexander Weiß, Thorsten Wagner
Format: Article
Language:English
Published: MDPI AG 2011-03-01
Series:Sensors
Subjects:
Online Access:http://www.mdpi.com/1424-8220/11/3/3135/
Description
Summary:Capacitive sensors are the most commonly used devices for the detection of humidity because they are inexpensive and the detection mechanism is very specific for humidity. However, especially for industrial processes, there is a lack of dielectrics that are stable at high temperature (>200 °C) and under harsh conditions. We present a capacitive sensor based on mesoporous silica as the dielectric in a simple sensor design based on pressed silica pellets. Investigation of the structural stability of the porous silica under simulated operating conditions as well as the influence of the pellet production will be shown. Impedance measurements demonstrate the utility of the sensor at both low (90 °C) and high (up to 210 °C) operating temperatures.
ISSN:1424-8220