Jon M Fessler

US Patent:

40308383, Jun 21, 1977

Filed:

Mar 1, 1976

Appl. No.:

5/662650

Inventors:

Jon Leroy Fessler - Tigard OR

Assignee:

Tektronix, Inc. - Beaverton OR

International Classification:

G01J 142

US Classification:

356219

Abstract:

An apparatus for facilitating the measurement of light parameters such as intensity of light when using a digital photometer or similar device whose readout incorporates a hold or memory function. The apparatus includes a photoelectric sensor receiving light to be measured, in conjunction with an optical view system, in a small acceptance angle and a light source providing an indication, in conjunction with the same optical view system, of the hold mode and means for visually connecting the measurement hold mode and the sensed light parameters together. Means are also provided for initiating the measurement.