Method for the Continuous Measurement of the Emissivity of a Heat Radiating Surface, and Method for Measuring the Temperature of such a Surface Using said First-Mentioned Method, and a Device for Implementing these Measurements

摘要

1,186,542. Emissivity and temperature measurement. M•R•STECHNIKAI KÍZPONTI KUTATË LABORAT6RIUM. March 20, 1967, No. 13029/67. Heading G1A. The emissivity and the temperature of the surface of a heated body are determined by an arrangement in which energy from the surface passes to a sensing element alternately directly and through a partially transmitting partially reflecting material which allows the passage of multiple reflection, the signals due to the alternate incidences being separated and brought into phase and their quotient being determined to indicate emissivity, the quotient of total directly received energy and this emissivity then being used to determine temperature. In order to eliminate the effect of radiation from the inside of the sensor housing, the incident radiation is chopped at a high frequency and a capacitor is included in series with the sensor. A disc situated between the surface and the sensor and comprising two semi-circles one transparent and the other semi-transparent and semi-reflective, is rotated to produce the two signals and they are separated by a synchronously driven switch. In a modification a pyrometer is inclined at an angle α to the surface under test, and a rotating disc the plane of which is set at an angle normal to -α alternately reflects and absorbs energy transmitted in that direction so that the pyrometer receives alternately direct radiation, and direct radiation plus that reflected by the disc: a mathematical analysis is included.