A family of high-accuracy, solid-state instruments ideally suited for internal combustion engine and vehicular applications has been developed. The core of each instrument is a programmable custom integrated circuit which produces exceptionally precise performance in applications as demanding as off-road equipment. The instruments are compatible with any form of resistive, voltage or current-producing sensor. Instrument outputs include displays in light emitting diode or liquid crystal formats and electronic signals for remote warning or equipment shutdown. Inherently rugged construction permits operation in sustained high-shock and high-vibration environments over wide temperature ranges. Improvements over existing products are delivered at comparable costs.