INSTRUMENT SCIENCE REPORT

CAL/FOS—016


THE LABORATORY ABSOLUTE PHOTOMETRIC CALIBRATION OF THE FOS



Gearge Hartig and Ralph Bohlin

June 1985

Abstract



A synopsis of Lhe laboratory measurements of the FOS absolute
spectrophotometric efficiency in most of its optical configurations is
presented. These measurements are compared with those pt-edicted on
the basis of earlier evaluations of the efficiencies of the individual
components: mirrors, dispersers and filters, and the Digicon quantum
efficiencies. Some evidence for minor degradation in perforrnance is
present; however, discrepancies between the predicted and rneasured
throughput are generally within the estirnated error. Final estimates
of the currenti FOS throughput for each disperser are tabulated.