Abstract

A method has been developed to investigate the sensitivity and photometric accuracy of a Fourier transform infrared (FT-IR) spectrometer by statistically analyzing a set of spectra of a 75 μm thick film of polyethylene terephthalate (PET). These tests were applied to three commercial FT-IR spectrometers. Although the photometric accuracy of all three instruments was generally better than 0.1%, small artifacts that could not be removed by signal averaging were often observed where strong bands should have a transmittance of less than 0.01%. Binding of the moving mirror of one of the spectrometers appeared to degrade its performance. When the standard deviation of the noise on 100% lines was calculated in the conventional way, none of the instruments gave efficient signal averaging after 25 scans had been coadded, because of small slopes in the baseline. By calculation of the noise level by successive difference, signal averaging was improved, but even with this approach the noise level on one of the instruments did not decrease after 100 scans had been averaged.

Accurate infrared transmittance measurements on optical filters using an FT-IR spectrometer

David A. C. Compton, John Drab, and Howard S. Barr
Appl. Opt. 29(19) 2908-2912 (1990)

Technique for Measuring Photometric Accuracy

R. C. Hawes
Appl. Opt. 10(6) 1246-1253 (1971)

Photometric Accuracy of Infrared Spectrophotometers

James E. Stewart
Appl. Opt. 2(12) 1303-1307 (1963)

Correction of interferogram data acquired using a focal plane FT-IR spectrometer system

Cong Gao, Jianhua Mao, and Ren Chen
Appl. Opt. 57(10) 2434-2440 (2018)

Precision of Color Measurement with the GE Spectrophotometer. II: Photometric Accuracy

Eugene C. Rhodes and Fred W. Billmeyer
Appl. Opt. 8(4) 769-773 (1969)