Automatic recording spectroradiometer system.

A versatile, mobile, automatic recording spectroradiometer of high precision and accuracy has been developed. The instrument is a single-beam device with an alternate reference beam intended primarily for measurements of spectral irradiance. However, it is equally useful for measurement of spectral radiance, transmittance, or reflectance. The system is programmed for automatic operation. The output is in the form of an automatic digital recording of both measurements and control data. Instrument operation integrates the following characteristics: wavelength-by-wavelength operation in intervals of 0.1 nm to 50 nm; time-integrated measurements of spectral flux; internal calibration reference source; and monitored signals for wavelength position, test source total output, and photodetector dark current. The system's operating characteristics and specifications have been determined and are set forth here. Performance for three types of sources and correction of measurements to zero-bandpass equivalence is demonstrated.