Description of an assembly of apparatus consisting of a “monochromatic colorimeter” (previously so called) and complete accessory apparatus for the determination of dominant wave-length, purity and transmission or reflection for white light under definitely specified conditions.
The apparatus is described as it has been actually used at the Bureau of Standards since March 1923.
Salient features of the apparatus and its use are:
- (1) The use of a specified artificial white light, field illumination being from incandescent filament lamps.
- (2) The diffusion sphere for the diffuse illumination of samples to be examined by reflection.
- (3) The convenient arrangement for handling samples to be examined in either transmitted or reflected light.
- (4) The convenient arrangement for the simultaneous adjustment of dominant wave-length, purity and brightness in the mixture field to match the juxtaposed sample field.
- (5) The analysis of the mixture of homogeneous and white light by a substitution flicker method.
Details of design of the apparatus, explicit directions for its use and data on its performance as regards precision and accuracy, including extensive tests of the additivity of homogeneous and white brightnesses, are given. These data support the theorem that brightnesses due respectively to homogeneous and heterogeneous stimuli are strictly additive.
© 1924 Optical Society of AmericaFull Article | PDF Article
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