Bently Nevada 990-05-70-02-00 990 XL Vibration Transmitter

Technical Specification Overview

The Bently Nevada 990-05-70-02-00 functions as a self-contained, 2-wire transmitter that converts a proximity probe signal into a standard 4-20 mA current loop. This device integrates the functions of a Proximitor sensor and a signal conditioner into a single unit. It measures the radial vibration of a rotating shaft and outputs a signal proportional to the overall peak-to-peak displacement. By providing a direct interface to a Distributed Control System (DCS) or Programmable Logic Controller (PLC), the 990 XL eliminates the need for specialized vibration monitor racks in non-critical machinery applications.

Design and Functional Capabilities

Engineers designed the 990-05-70-02-00 to operate within a 5-meter total system length, typically pairing it with a 3300 XL 8mm proximity probe. This specific model features a full-scale range of 0-5 mils (0-125 µm) peak-to-peak, providing high-resolution data for precise vibration tracking. Furthermore, the transmitter includes a “Prox Out” buffered signal port. This allows technicians to connect portable diagnostic equipment, such as a field data collector, to view the raw vibration waveform without interrupting the 4-20 mA control loop.

• Manufacturer: Bently Nevada
• Model Number: 990-05-70-02-00
• Series: 990 XL Vibration Transmitter
• Full-Scale Range: 0-5 mils pp
• System Length: 5.0 Meters
• Mounting Option: 35mm DIN rail mount
• Agency Approval: Standard / No hazardous area
• Output Signal: 4-20 mA DC (Proportional to vibration)
• Supply Voltage: +12 to +35 Vdc
• Enclosure Material: Polyphenylene Sulfide (PPS) and Stainless Steel

Operational Impact and Industrial Applications

This vibration transmitter actively simplifies the integration of machinery protection into existing plant control architectures. Because it uses a standard 4-20 mA interface, it allows for easy trending and alarming within the plant’s HMI environment. Consequently, maintenance teams can implement cost-effective monitoring for general-purpose equipment like motors, fans, and pumps. The 990-05-70-02-00 ensures that operators receive immediate notification of mechanical issues such as rotor imbalance or shaft misalignment, thereby preventing unexpected downtime.

Primary industrial applications include:

• Centrifugal Fans: Monitoring rotor stability in industrial ventilation and cooling towers.
• Electric Motors: Tracking bearing health and vibration levels in large driver units.
• Centrifugal Pumps: Providing continuous protection for fluid transport systems.
• Integrated Control: Directing vibration data into a PLC for automated asset management.

Mechanical Integrity and Reliability

Bently Nevada utilizes high-durability materials to ensure the 990-05-70-02-00 performs reliably in punishing industrial environments. The transmitter housing features excellent resistance to electromagnetic interference (EMI), which prevents signal noise from affecting the accuracy of the 4-20 mA loop. Additionally, the DIN rail mounting option facilitates rapid installation within existing electrical cabinets. The unit also includes internal protection against reversed polarity and over-voltage, ensuring that the electronics remain safe during commissioning and routine maintenance.