Photometer

Abstract

A photometer is providing including light detecting means for detecting incident light and generating electric signals in response thereto as a measure of the incident light thereon, and optical means for guiding light to the light detecting means from a standard light source in a calibration mode and from an object, a photometric quantity of which is to be measured, in a measurement mode. Control means are adapted to generate calibration control signals for carrying out a calibration mode wherein a photometric quantity value Dstd of the standard light source and a measured value Rstd corresponding to the intensity of the standard light source detected by the light detecting means are stored in a memory, and light measurement control signals for carrying out a measurement mode wherein a photometric quantity value Rm corresponding to the photometric quantity of the object measured by the light detecting means is also stored in memory such that a CPU or similar computing means can communicate with the memory and compute a photometric quantity value R of the object according to the formula R=Rm.times.(Dstd/Rstd).

Dependencies are inferred from the claim text.