Comparative study of ZnCr2O4-K2CrO4 ceramic humidity sensor using computer controlled humidity measurement set-up


Kavasoglu N., Kavasoglu A., Bayhan M.

SENSORS AND ACTUATORS A-PHYSICAL, cilt.126, sa.2, ss.355-361, 2006 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 126 Sayı: 2
  • Basım Tarihi: 2006
  • Doi Numarası: 10.1016/j.sna.2005.10.049
  • Dergi Adı: SENSORS AND ACTUATORS A-PHYSICAL
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.355-361
  • Hacettepe Üniversitesi Adresli: Hayır

Özet

A home-made ZnCr2O4-KCrO4 ceramic humidity sensor was studied using a commercially available reference humidity sensor, SHT75 from Sensirion. The main advantages of our developed set-up for humidity measurements are low cost and high resolution yielding a full set of information on the variation of humidity. Air moisture sensitive ceramic body prepared using K2CrO4 (20%) in ZnCr2O4 was produced from the solid-state reaction between zinc oxide and chromite oxide at high temperatures. The dc resistance as a function of relative humidity (RH) showed a strong dependence, decreasing over several orders of magnitude with increasing humidity being a smooth exponential. The air moisture dependent resistance of the ceramic sensor is converted into voltage signals using a circuitry. Basically it consists of an operational amplifier and an A/D converter. Long-term stability measurements showed that ZnCr2O4-K2CrO4 ceramic system has potential use as an active material in humidity sensors. (C) 2005 Elsevier B.V. All rights reserved.