THE NIST 30 MHZ LINEAR MEASUREMENT SYSTEM

An automated linear measurement system (LMS) has been developed to det ermine the nonlinearity of a tuned 30 MHz power detector over a 6.021 dB range. This detector uses a single thermistor bead design with ther mal isolation to obtain nearly linear tracking over a 4:1 change in in put power. The nonlinear correction for this change, determined by the LMS, is on the order of 1.00030 (+130 muB) for the detector presently in use. Initial experiments indicate an expanded uncertainty of +/- 0 .138% (+/- 598 muB), which is based upon Type A and Type B components.