Product Overview

The Bently Nevada 991-06-70-01-05 is a specialized Thrust Transmitter designed to provide a continuous 4 to 20 mA signal proportional to axial shaft displacement. This device is an essential solution for Original Equipment Manufacturers (OEMs) of centrifugal air compressors, industrial pumps, and high-speed motors who require integrated machinery protection without the complexity of a full rack-based system. By accepting inputs from a 3300 NSv proximity probe, the 991 transmitter facilitates real-time monitoring of thrust bearing health, ensuring that axial movement remains within safe operational limits to prevent catastrophic mechanical failure.

Hardware Parameters

• Model Number 991-06-70-01-05

• Input Signal Compatible with 3300 NSv Proximity Probes (5m or 7m systems)

• Output Signal 4-20 mA DC (proportional to axial displacement)

• Diagnostic Interface Coaxial connector for buffered "PROX OUT" and gap voltage

• System Adjustments Non-interacting zero and span potentiometers

• Protection Circuitry Power-up Inhibit to suppress voltage transient errors

• Supply Voltage +12 to +35 Vdc

• Environmental Rating Designed for hazardous area installations with appropriate barriers

• Physical Weight 0.44 kg

• Standard Scaling Typically 25-0-25 mils or 40-0-40 mils depending on configuration

Industrial Applications

The 991-06-70-01-05 is primarily utilized for monitoring the thrust position of rotating shafts in compact machinery. It is widely applied in the aero-derivative turbine market, small-scale power generation, and wastewater treatment blowers. Because the transmitter incorporates an internal Proximitor, it significantly reduces the installation footprint by removing the need for separate signal conditioners. The buffered output allows maintenance teams to connect portable diagnostic equipment, such as data collectors or oscilloscopes, to analyze vibration frequencies and gap voltage without interrupting the primary 4-20 mA control loop. This makes it a preferred choice for integrated PLC or DCS-based machinery protection strategies.