Answer to Question #24526 in Inorganic Chemistry for shafiqah asim
why liquid crystal look coloured
The intrinsic color temperature response of the liquid crystal should be known prior to its use. This requires the development of calibration methods for extracting the intrinsic color-temperature response of the liquid crystals. The calibration efforts can be either successive isothermal or gradient technique. In the successive isothermal method, a temperature-controlled test surface and a color measurement system are used to generate liquid crystal color-to-temperature calibration data. Color image of the test surface is taken after bringing the test surface and the liquid crystal to its event temperature. Then an average color value is computed and stored with the temperature of the test surface. This process is repeated at subsequently higher temperatures until the clearing point temperature is reached. Though it seems to be simple, the successive isotherm method can be very time consuming with a large amount of data processing requirement. In gradient methods, the liquid crystal is subjected to a variable color-temperature distribution such as linear temperature gradient. The gradient technique provides a continuous representation of the entire color temperature response of liquid crystals using a single color image. It provides a much higher color temperature resolution than the successive-isotherm method in a fraction of the time and with much less data processing.