PURPOSE: To accurately detect the pollution degree of oil without receiving the effect due to the absorption of light by the film adhered to the surface of glass and the characteristic change in the light emitting intensity of a light emitting element, by measuring the intensities of lights passing through two oil films having different thicknesses.
CONSTITUTION: The light from the light emitting surface 1-a of a light emitting element 1 is allowed to reach light receiving surfaces 2-a, 2-b through the light paths respectively having distances Da, Db in oil and the intensities of both lights are set to Ia, Ib. The intensities Ia, Ib calculated by operation are shown by the light emitting intensity of the light emitting element, the absorption coefficient of light due to the pollutant film on the surface of glass, the change coefficient of the light emitting intensity of the light emitting element and a pollution degree α etc. but, if the pollution degree α is calculated from the intensities Ia, Ib the absorption coefficient and the change coefficient are erased. By this method, the pollution degree of oil can be accurately detected without being affected by the pollution on the surface of glass and the characteristic change in the light intensity of the light emitting element.
AKATSUCHI HAJIME
ISHIDA TOSHINOBU
NOZAWA MASAE
NIPPON DENSO CO
| JPS5529780A | 1980-03-03 | |||
| JPS5599046A | 1980-07-28 | |||
| JPS60111946A | 1985-06-18 |