Product Overview

The Bently Nevada 990-04-50-01-05 is a specialized vibration transmitter engineered to provide continuous, non-contact machinery monitoring for industrial rotating assets. This integrated signal conditioner interfaces directly with a 3300 NSv proximity probe, converting eddy current displacement signals into a standardized 4-20mA analog output. Designed primarily for OEMs and facilities requiring essential vibration trending, it allows for seamless integration into PLCs, DCS, or SCADA systems. While optimized for simplified machinery protection, the unit includes a "Prox Out" coaxial connector, allowing maintenance teams to access raw dynamic signals for temporary diagnostic troubleshooting using external analyzers.

Hardware Parameters and Technical Specifications

This transmitter is built to operate within a two-wire current loop, combining high-precision signal conditioning with a ruggedized form factor suitable for high-density industrial installations.

• Model Number 990-04-50-01-05

• Measurement Range 0 to 100 µm (0 to 4 mils) peak-to-peak vibration

• System Length Compatibility Optimized for 5.0-meter (16.4 ft) system lengths (Option -04)

• Output Signal 4 to 20 mA DC, proportional to vibration amplitude

• Mounting Configuration 35mm DIN-rail clips (Option -01)

• Connector Type 4-terminal block with a 3-pin MIL-C-5015 top-exit connector (Option -05)

• Input Excitation 12 to 35 VDC (Loop-powered)

• Frequency Response 5 Hz to 5 kHz (± 3 dB)

• Isolation Non-isolated dynamic signal available via coaxial "Prox Out" port

• Casing Material Polyphenylene sulfide (PPS) and AISI 304 Stainless Steel base

• Weight 0.44 kg (approx. 0.97 lbs)

Industrial Applications and Operational Use Cases

The 990-04-50-01-05 is a vital component for Turbine Supervisory Instrumentation (TSI) in applications where compact footprints and simplified signal paths are required.

• Centrifugal Air Compressors Real-time monitoring of shaft vibration to detect rotor unbalance, mechanical looseness, or bearing wear.

• Industrial Pumps and Motors Providing a direct analog interface for plant control systems to trigger automated alarms or machinery trip logic.

• Cooling Tower Fans Monitoring gearbox and fan shaft vibration levels in remote locations without the need for complex monitoring racks.

• OEM Machine Protection Integrated as a standard vibration sensing solution for equipment manufacturers to provide basic asset health trending.

• Basic Asset Trending Ideal for secondary or "balance of plant" (BoP) equipment where 4-20mA trending is sufficient for maintenance planning.

For advanced diagnostic sessions, the 990/991 Test Adapter should be utilized to provide proper signal isolation and inversion when connecting to oscilloscopes or FFT analyzers, ensuring the integrity of the 4-20mA loop remains uncompromised.