In the course of infrared studies on dense materials with double-beam instruments, it is frequently necessary to attenuate the reference beam in order to be able to record the spectrum. Also, in some studies, particularly with the interaction of gas with a solid, the sample transmission
can vary with experimental conditions, so that continual adjustment of reference beam intensity must be made. Such adjustments are very inconvenient to make with wire mesh screens or slotted shutters because these produce a step-by-step attenuation. Continuous attenuation is desirable for
such purposes. Some continuously-variable attenuators made of tilting vanes (1) or wire screens (2) have been described. Such devices are useful but have the disadvantages of large size and non-linearity of attenuation. The rotary motion must be controlled precisely and, because
of the rotation of such a device, a substantial fraction of the reference beam space is taken up so that large compensating cells cannot be accommodated.
School of Chemistry Rutgers—The State University New Brunswick, New Jersey
Publication date: November 1, 1964
More about this publication?
The Society publishes the internationally recognized, peer reviewed journal, Applied Spectroscopy, which is available both in print and online. Subscriptions are included with membership or can be purchased by institutional or corporate organizations. Abstracts may be viewed free of charge. Previously published as Bulletin (Society for Applied Spectroscopy)