Temperature sensing with thermochromic liquid crystals
Temperature sensing with thermochromic liquid crystals
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DOI：
10.1007/s003480000154
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发表时间：
2001-02-01
影响因子：
2.4
通讯作者：
Praisner, TJ
中科院分区：
文献类型：
--
作者：
Smith, CR;Sabatino, DR;Praisner, TJ
本文综述了热致变色液晶在流体流动温度测量中的应用。实验方面，包括应用，照明，记录和校准的液晶固体表面上，以及在流体悬浮液中，进行了讨论。由于液晶的各向异性光学特性，轴上照明/观察布置与原位校准技术相结合，通常可以提供最准确的温度评估。然而，在不可能进行轴上观察的情况下，可以采用校准技术，这减少了与离轴观察和照明布置相关联的不确定性。已经确定的是，使用在色谱上显示线性趋势的色调定义产生与温度的最准确的相关性。宽带和窄带热致变色液晶校准技术两者的不确定性可由于滞后效应而增加，滞后效应在液晶的温度超过其最大活化温度时发生。虽然液晶通常用于提供时间平均温度测量，但是可以使用允许监测时间变化的技术。选定的例子说明使用热致变色液晶显示，并报告温度测量的不确定性的调查。
A review of the most recent developments in the application of thermochromic liquid crystals to fluid flow temperature measurement is presented. The experimental aspects including application, illumination, recording, and calibration of liquid crystals on solid surfaces, as well as in fluid suspensions, are discussed. Because of the anisotropic optical properties of liquid crystals, on-axis lighting/viewing arrangements, combined with in-situ calibration techniques, generally provide the most accurate temperature assessments. However, where on-axis viewing is not possible, calibration techniques can be employed, which reduce the uncertainty associated with off-axis viewing and lighting arrangements. It has been determined that the use of hue definitions that display a Linear trend across the color spectrum yield the most accurate correlation with temperature. The uncertainty of both wide-band and narrow-band thermochromic liquid crystal calibration techniques can be increased due to hysteresis effects, which occur when the temperature of the liquid crystals exceeds their maximum activation temperature. Although liquid crystals are commonly used to provide time-mean temperature measurements, techniques are available which allow the monitoring of temporal changes. Selected examples illustrating the use of thermochromic liquid crystals are shown, and a survey of reported temperature measurement uncertainties is presented.