An infra-red spectrometer to operate over the range 8-100 micrometres

Infrared Spectrometry

“…Design of infrared, filter-grating spectrophotometers was discussed by Alpert (17), while Girard (206) described some results obtained with an instrument in which the entrance and exit slits were replaced by a two-dimensional set of alternately transparent and opaque zones; a luminosity gain greater than 100 over the conventional slit system w-as claimed. Other instruments described were: an instrument covering the 1250-to 100-cm.-1 range with 0.5-cm.-1 resolution (253); a highresolution instrument using one coarse grating in higher orders for the 1-to 40-micron region (459); two other highresolution instruments (212,368); a double-beam instrument with CsBr fore-prism (499); and a two-wavelength, two-frequency, ratio-recording infrared spectrometer-analyzer (38). Several far-infrared instruments are referred to later.…”