(under subclass 46) Subject matter wherein the means to compare or facilitate the comparison of the standard and unknown radiation includes means to modulate mechanically or optically the standard or the unknown radiation.
(1) Note. The modulated unknown or standard radiation may include portions of other radiation.
(2) Note. Color discrimination and optical attenuation means may be part of the combination claimed.
SEE OR SEARCH THIS CLASS, SUBCLASS:
217, for modulation type photometers where temperature is not involved.
418, for shade or color tests where color and intensity of light is included and an incandescent standard may be involved but temperature is not involved and modulation of the light takes place.
425, for light intensity comparison of shade where temperature is not involved but modulation may be involved.
SEE OR SEARCH CLASS
250, Radiant Energy,
232+, for optical modulators or flickering beam photocell circuits of general usage.
374, Thermal Measuring and Testing,
121+, for radiation pyrometers which utilize modulating means.
