Share

IIR document

Developing of novel optical-fiber type temperature and humidity sensors.

Author(s) : DANG C. B., HIHARA E., LIANG C.

Summary

A novel temperature/humidity sensor concept is proposed in this paper to be used in the air-conditioning and refrigeration area. The structure of the sensor is very simple, which is a plastic optical fiber, with a core area to transmit light and a cladding layer to adjust the output light intensity. Alteration of environmental temperature or humidity is detected by the change in the refractive index of the cladding layer due to the absorption of water vapour into the polymer membrane. The material of the cladding is selected so that its refractive index is larger than that of the core area under low humidity condition. When light is introduced to the optical fiber, large portion of the light may escape by the infraction from the core area to the cladding layer, and finally leaks into the environment. With the increase in the environmental humidity, the refractive index of the cladding layer decreases, therefore much more light is reflected back to the core and transmitted through the optical fiber to the output; the change in light intensity is therefore detected and converted into the change in the humidity. Since the refractive index of the cladding layer is also the function of environmental temperature, a temperature sensor is also manufactured by this concept. Performance tests have been conducted to validate the concept of this novel temperature/humidity sensor. The core area was made from polymethylmethacrylate. A blend polymer of polyvinylpyrrolidone and polyvinylfluoride with mixing ration of 1:3 was selected to fabricate the cladding layer for the temperature sensor, which showed a satisfactory sensitivity to the change in environmental temperature, and did not affected by the change in humidity. A blend polymer of polymethylmethacrylate and polyvinylfluoride (1:3) was selected for humidity sensor. Experimental results showed that the humidity sensor is sensible to the change of both the temperature and relative humidity.

Available documents

Format PDF

Pages: ICR07-E1-997

Available

  • Public price

    20 €

  • Member price*

    Free

* Best rate depending on membership category (see the detailed benefits of individual and corporate memberships).

Details

  • Original title: Developing of novel optical-fiber type temperature and humidity sensors.
  • Record ID : 2007-2500
  • Languages: English
  • Source: ICR 2007. Refrigeration Creates the Future. Proceedings of the 22nd IIR International Congress of Refrigeration.
  • Publication date: 2007/08/21

Links


See other articles from the proceedings (839)
See the conference proceedings

Indexing