A FIBEROPTIC HIGH-TEMPERATURE SENSOR

A wavelength-encoded high-temperature fiber-optic sensor is described. A 0.77 mm thick single-crystal sapphire flat serves as the sensing el ement, which can withstand temperatures as high as 2000-degrees-C. The polarization state of the incident white light is modulated by the hi gh birefringence of the sapphire flat and becomes a wavelength-encoded signal on the output of a CCD array receiver. An accuracy of greater than 0.15% full scale has been achieved over the measurement range 30- 1340-degrees-C with this sensor. The great advantages of this fiber-op tic high-temperature sensor are its simplicity and long-term stability .