The Bently Nevada 991 Thrust Transmitter provides a 4-20 mA signal proportional to thrust position and is designed for use on smaller, non-critical machinery. Its primary use is on centrifugal air compressors with fluid-film thrust bearings. The 991 Thrust Transmitter can measure up to 1.2 mm or 50 mils of total thrust movement.

The 991 thrust transmitter is a 2-wire, loop-powered device that accepts input from Bently Nevada's 3300 NSv proximity probes and matching extension cables (available in 5 and 7 meter system length options). The transmitter conditions the signal into appropriate engineering units proportional to the shaft's axial position, and provides it as a 4 to 20 mA industry-standard signal for input to the control system where machinery protection alarming and logic occurs.