Product Overview

The Bently Nevada 990-05-70-03-05 is a high-precision, standalone vibration transmitter engineered to provide continuous machinery protection through an industry-standard 4-20 mA loop. This module serves as an integrated solution by combining the signal processing of a Proximitor sensor with a transmitter interface, effectively removing the requirement for a separate monitor rack for basic vibration trending. It is designed to interface with 3300 NSv proximity probes and extension cables to monitor the radial vibration of fluid-film bearing machines. The device converts the complex eddy current signal into a linear current output proportional to the peak-to-peak vibration amplitude, facilitating direct integration into Distributed Control Systems (DCS) or Programmable Logic Controllers (PLC).

Hardware Parameters

• Model Number 990-05-70-03-05

• Input Compatibility 3300 NSv Proximity Transducer System

• Output Signal 4 to 20 mA DC (proportional to vibration)

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

• System Length 5.0 meters (Option -05)

• Full-Scale Range 0 to 100 µm (4 mils) peak-to-peak (Option -70)

• Mounting Options 35mm DIN-rail or bulkhead mounting

• Calibration Controls Non-interacting zero and span potentiometers

• Fault Logic Integrated "Not OK" / Signal Defeat circuitry to prevent false alarms

• Power Supply +12 to +35 Vdc

• Physical Weight 0.46 kg

Industrial Applications

The 990-05-70-03-05 is primarily deployed for the protection of centrifugal air compressors, small pumps, fans, and motors. It is particularly valued in OEM skids where space is limited and a full Bently Nevada 3500 rack is not cost-effective. The transmitter allows operators to trend vibration levels over time while providing a secondary buffered output for field technicians. Using the coaxial BNC connector, diagnostic teams can connect portable oscilloscopes or data collectors to analyze frequency spectrums, identifying specific faults like unbalance, misalignment, or bearing degradation without interrupting the primary control loop. Its robust construction and hazardous area approvals (ATEX/IECEx/CSA) make it suitable for demanding environments in the oil and gas and power generation sectors.