Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

TEMPERATURE DISTRIBUTION MEASUREMENT USING RATIO OF SCATTERED LIGHT INTENSITIES FROM THERMO-CHROMIC LIQUID CRYSTAL: UNCERTAINTY EVALUATION

Get access (open in a dialog) DOI: 10.1615/IHTC16.tpm.024087
pages 8935-8941

Abstrakt

In this paper, a novel temperature-measurement method utilizing thermo-chromic liquid crystal (TLC) was proposed. As is well known, the color of TLC changes with temperature; therefore, the distribution of the temperature can be simply measured by interpreting the color change into temperature. In the present method, temperature was determined using the intensity ratio of scattered light on TLC at two different wavelengths. This method could significantly minimize the influence of fluctuations of the light irradiation and unknown transmittance of the optical path; enabling the range of measurable temperature far broader than conventional methods. The target object of the temperature measurement was a planar copper plate with a TLC sheet on its top. Images of light intensity were captured by a pair of monochrome cameras and a half mirror to obtain two identical images of the intensity distribution for the ratio analysis. Values of intensity on each pixel were averaged using 2-500 images to eliminate capturing noise. Results demonstrated that the range of measurable temperature attained in the present study was 5-41°C for the wavelength combination of 420nm/405nm. Further, measurement uncertainty of the proposed method was evaluated, and it was found that the uncertainty was less than 1°C within the range of temperature 17-31°C. Relationship between the number of images used in the image processing and the uncertainty was also examined and discussed.