This Technical Report outlines procedures for determining the spectral responsivity function of photodetectors. It contains two parts:

1. Determination of the relative spectral responsivity function

Various methods are presented and instrumental details are discussed. Sources of errors are listed together with diagnostic tests and proposals for remedial action.

2. Absolute calibration

Three different methods are presented for transforming relative spectral data into absolute values.

The report is intended to serve as a guide in assembling, testing, or modifying new or existing instruments. Its purpose is to describe options in the development of instrumentation, not to present solutions for individual cases.

The report consists of 73 pages and 10 figures.