Abstract

A detection and amplification system for a recording infra-red spectrophotometer has been designed and built around a pin-type thermocouple, 13-cycle chopper, 13-cycle amplifier and synchronous rectifier. The subsequent circuits modulate the rectified output to 60 cycles for operation of a 2-phase servo balance motor and automatic suppression of the wave-length scanning speed whenever a pen servo error exists. An independent circuit employs a tapped potentiometer as an electrical cam to control the monochromator slit width to give relatively constant energy output at seven energy levels. A total of eighteen tubes are employed, with three of them in the 13-cycle amplifier. The first tube is operated at reduced voltage with a floating grid following a 300:1 gain transformer. Special construction of the preamplifier greatly reduces the susceptibility to 60-cycle pick-up over previous amplifiers.

© 1950 Optical Society of America

Performance of a Double-Beam Recording Infra-Red Spectrophotometer

John U. White and Max D. Liston
J. Opt. Soc. Am. 40(2) 93-101 (1950)

A Ratio-Recording Double-Beam Infra-Red Spectrophotometer with Automatic Slit-Control*†

D. F. Hornig, G. E. Hyde, and W. A. Adcock
J. Opt. Soc. Am. 40(8) 497-503 (1950)

Construction of a Double Beam Recording Infra-Red Spectrophotometer

John U. White and Max D. Liston
J. Opt. Soc. Am. 40(1) 29-35 (1950)

A Double-Beam, Percent Transmission Recording Infra-Red Spectrophotometer

N. Wright and L. W. Herscher
J. Opt. Soc. Am. 37(3) 211-216 (1947)

Recording and Control System for Infra-Red Spectrophotometer

Gerald M. Rassweiler, Max D. Liston, J. F. Lash, and D. L. Fry
J. Opt. Soc. Am. 37(12) 963-974 (1947)