Automatic Bridge Balance for Nuclear Spin Resonance Spectrometer

Abstract

Troublesome changes of the bridge balance in a twin‐T nuclear resonance bridge have been eliminated by the application of a voltage‐sensitive condenser. A small amplitude, high‐frequency modulation voltage applied to the condenser senses any deviation from balance, and a servo loop provides a dc correction voltage which maintains the bridge balance. No apparent deterioration of the spectrum results from modulation of the bridge.