A lightweight, compact thermionic ionization gauge control is described which is simpler and more efficient than conventional units. Emission regulation is achieved by using a transistorized feedback amplifier to maintain constant emission current in the presence of variations in supply voltage and pressure. Ion current is measured from 10−8to 10−4amp, in a single range, using a Zener diode as a logarithmic element in the collector circuit. Two control units were successfully flown aboard the IGY Aerobee‐Hi rocket NN3.14F.