Conversion of an Infrared Spectrophotometer Incorporating a Memory System to Double Beam Operation

Abstract

40STEPHEN ]. NETTEL of the output, while the spacing of the pulses is a convenient indication of the time. Longer signals could be recorded with a moving camera, or with an electromechanical oscillograph. For signals varying more slowly than a few cycles per second the output is obtained from the recording milliameter.The six volt upper limit of the input range is determined by the maximum input voltage of the converter. The lower limit is determined by the hum and noise of the amplification stage output. The range achieved THE REVIEW OF SCIENTIFIC INSTRUMENTS was sufficient for the intended application, but might be extended by improving the signal-to-noise ratio of the dc amplifier section. ACKNOWLEDGMENTSThe writer is grateful for the stimulating discussions he has had with many members of the Marconi research staff. He is very much indebted to his senior Mr. W. J.Battell, who contributed towards both the design and troubleshooting of the amplifier.