Abstract

The limiting sensitivity of an alternating-current system of amplification is considered. The practical limit is determined theoretically and experimentally for measured circuit parameters. A particular circuit using an electrometer-tube and a cesium-antimony cell is shown to be capable of detecting 4.5×10⁻¹⁵ watt in 30 seconds. Data on various input-tubes and photoelectric cells are given.

© 1939 Optical Society of America

The Measurement of Light Scattered by the Upper Atmosphere from a Search-Light Beam

E. A. Johnson, R. C. Meyer, R. E. Hopkins, and W. H. Mock
J. Opt. Soc. Am. 29(12) 512-517 (1939)

A Densitometer Employing an Alternating Current Amplifier

Lewis P. Tabor
J. Opt. Soc. Am. 29(1) 32-34 (1939)

Wide Range Intensity Measurements in Photoelectric Spectrophotometry

Walter C. Bosch and Barremore B. Brown
J. Opt. Soc. Am. 29(11) 466-469 (1939)

An Automatic Spectral-Sensitivity Curve Tracer

T. B. Perkins
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Direct Measurement of the Intensity Distribution in Fresnel Diffraction Patterns

C. D. Hause, J. G. Woodward, and C. E. McClellan
J. Opt. Soc. Am. 29(4) 147-151 (1939)