Overview
Manuals
Principle
Primary Applications
Features:
- 991 Thrust Transmitter
- A Power-up Inhibit circuit eliminates signal errors due to line voltage transients
- Non-interacting zero and span potentiometers under the Transmitter label supports loop adjustment
The 991 Thrust Transmitter is intended primarily for the original equipment manufacturers (OEMs) of centrifugal air compressors or small pumps, motors, or fans who prefer to provide a simple 4 to 20 mA proportional axial displacement (thrust) signal as the input to their machinery control system.
The transmitter is a 2-wire, loop-powered device that accepts input from our 3300 NSv proximity probe and its matching extension cable (available in 5 m and 7 m system length options). The transmitter conditions the signal into appropriate engineering units proportional to the shaft’s axial position1, 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.
The 991-25-50-01-05 Bently Nevada 991 Thrust Transmitter may still be available for purchase and support from Moore Automated Company beyond End-Of-Life (EOL) by the manufacturer (OEM).
Bently Nevada 991-25-50-01-05 991 Thrust Transmitter Manuals(Datasheets), Link
Important Notice: Other accessories, manuals, cables, calibration data, software, etc. are not included with this equipment unless listed in the above stock item description. All prices are shown in USD.
Probe adjustment and range are critical in thrust position measurements. Incorrect probe gap settings may prevent the transmitter from reaching full-scale in either the normal or counter directions (no machinery monitoring). For proper adjustment, follow the instructions in the manual.
The Type 991 transmitter is primarily targeted at original equipment manufacturers (OEMs) of small, non-critical mechanical equipment that requires simple interface connections with control systems or PLCs. Common applications include:
Centrifugal air compressors: typically employing hydrodynamic thrust bearings.
Small pumps and fans: suitable for higher-cost rack-mount monitoring systems.
Industrial motors: monitoring axial position to prevent contact between internal components.
