Bently Nevada 990-05-70-03-05 Vibration Transmitter Module

The Bently Nevada 990-05-70-03-05 is a 990 Series vibration transmitter designed to convert shaft vibration signals from a compatible proximity probe system into a standard 4-20 mA output. It provides a simple interface between rotating machinery monitoring points and plant control systems, allowing vibration measurements to be transmitted directly to PLC, DCS, SCADA, or process monitoring equipment.

Product Description

The 990 Series transmitter is intended for continuous vibration monitoring on rotating machinery. It accepts the signal from a Bently Nevada 3300 NSv proximity probe and extension cable assembly, processes the vibration measurement, and generates a proportional 4-20 mA output signal for control and indication systems.

Unlike rack-based machinery protection systems, the transmitter provides a compact field-mounted solution for applications that require a direct analog representation of shaft vibration. This approach is commonly used on OEM equipment where integration with an existing control system is preferred over a dedicated vibration monitoring rack.

Model Configuration

The ordering code of 990-05-70-03-05 identifies a specific transmitter configuration:

• 990 - 990 Series Vibration Transmitter

• 05 - Full-scale range: 0-5 mils pp (0-125 um pp)

• 70 - 7.0 m system length

• 03 - DIN rail clip and screw mounting option

• 05 - Agency approval or special option designation

Technical Specifications

Signal Conversion and Output

The transmitter continuously measures shaft vibration detected by the connected proximity probe system and converts the measurement into a process-industry standard 4-20 mA current signal. This allows vibration values to be transmitted over long distances with high noise immunity and integrated directly into analog input channels.

A linear current output also simplifies trending, alarming, and condition monitoring within plant automation systems without requiring dedicated vibration monitoring software.

Sensor Compatibility

This configuration is designed for use with a 3300 NSv proximity probe and matching extension cable arrangement. The specified 7.0 m system length forms part of the calibrated transducer system and should be maintained when replacing components to preserve measurement performance.

The transmitter relies on the proximity probe system to measure shaft movement while providing signal conditioning, scaling, and analog retransmission functions.

Application Considerations

The 990 Series transmitter is commonly applied to centrifugal air compressors, small pumps, motors, fans, and similar rotating equipment where shaft vibration must be monitored continuously.

Because the device delivers a standard process signal rather than a proprietary output, it can be incorporated into machine control and condition monitoring strategies using existing PLC or DCS infrastructure.

Frequently Asked Questions

Q: What measurement range does the 990-05-70-03-05 configuration provide?

A: This configuration is scaled for 0-5 mils peak-to-peak shaft vibration, equivalent to approximately 0-125 um pp.

Q: Can the transmitter be connected directly to a PLC analog input?

A: Yes. The transmitter provides a standard 4-20 mA output signal intended for direct connection to compatible PLC, DCS, or other process control system analog inputs.

Q: Does the transmitter measure vibration by itself?

A: No. The transmitter requires a compatible 3300 NSv proximity probe and extension cable system. The probe performs the displacement measurement, while the transmitter conditions and retransmits the signal.