A two-channel photometer for use in small sounding rockets

A two-channel photometer has been designed as primarily for use in small sounding rockets. Four have been flown sucessfully to study the diurnal variation of the 0₂ (¹[delta]g) concentration by measuring 1.27 [mu] radiation from the (¹[delta]g - ³[sigma]g⁻) transition. The performace was satisfactory and comparable to similar instruments. The goal was to develop a small photometer with optics suitable for small detectors including photomultipliers. This was achieved, with the light baffling system being particularly good. The optics, electronics, and mechanical considerations are discussed, with a few sources of difficulty being pointed out. The laboratory and field calibration procedures which were followed are described.