INTRODUCTION The Racal-Dana RF Level Meter Model 9303 is a versatile, microprocessor controlled instrument. It will make measurements on signals having crest factors up to 15 and r.m.s. voltage levels between 30 pV and 3.162 V. The instrument has an auto ranging facility, but provision for manual setting of the range is provided. The full quoted accuracy is obtained over a frequency range from 10 kHz to 2 GHz. The instrument features an auto calibration facility. The calibration factors relating to the measuring heads are stored during the calibration procedure, and are used to adjust the displayed measurement without further operator action. A calibration signal source is provided for use should re-calibration of the measuring heads become necessary. The instrument measures the true r.m.s. voltage of the applied signal. This may be displayed in voltage units, or converted to: (a) Indication of power, computed as V^/R, where R is a resistance value stored in the instrument. (b) Indication of power relative to a power level which has been stored in the instrument. This may be displayed as a numeric ratio or in dB. (c) Indication of the percentage difference between the measured voltage or the computed power and a voltage or power level which has been stored in the instrument. (d) Indication of the difference between the measured voltage or the computed power and a voltage or power level which has been stored in the instrument. (e) Indication of the ratio of the measured voltage to a voltage level which has been stored in the instrument. This may be displayed as a numeric ratio or in dB. The instrument features a large, four digit, liquid crystal display (LCD). Coarse and fine light dot displays form part of the display, and provide a pseudo-analogue form of indication. Units annunciators, operation limit warning indicators and calibration factor indicators are also incorporated.