Calibration Of A 1 Meter Diameter Normal Incidence Extreme Ultraviolet Telescope/Spectrometer

We have built a 1 meter normal incidence telescope, with a normal incidence concave diffraction grating spectrometer at its focus. The instrument's spectral coverage is 350 to 1150 Å with a spectral resolution of 5 Å and a peak effective area of 6 cm2 at 500 Å . The instrument was launched on an Aries sounding rocket on November 27, 1983 in an effort to determine the hydrogen and helium abundance in the local interstellar medium. Here we present a description of this instrument with the primary emphasis on the methods used to calibrate it.