Product Overview
In critical rotating machinery applications, precise vibration monitoring prevents costly failures. The Bently Nevada 990-04-70-03-01 990 Vibration Transmitter delivers reliable, real-time vibration data with a 4-20 mA output. Designed for non-hazardous, Zone 2, or Div 2 hazardous areas, this transmitter accepts one 3300 NSv proximity probe and extension cable. Its compact design and robust features make it an ideal upgrade for existing vibration monitoring systems.
Technical Specifications
The Bently Nevada 990-04-70-03-01 includes several key performance parameters derived from the product datasheet:
| Parameter |
Value |
| Full-scale option |
0-4 mils pp (0-100 μm pp) |
| System length option |
7.0 meters (23.0 feet) |
| Mounting option |
DIN clips and screws |
| Agency approval option |
CSA Division 2 |
| Input |
Accepts 1 non-contacting 3300 NSv Proximity Probe |
| Power |
+12 to +35 Vdc at transmitter terminal |
| Maximum loop resistance |
1,000 Ω including cable at 35 Vdc |
| Current limiting |
23 mA typical |
| Weight |
0.43 kg (0.9 lbm) |
| 4 to 20 mA loop accuracy |
Within ±1.5% over full-scale range |
| Probe gap |
0.5 to 1.75 mm (20 to 55 mils) |
| Frequency response |
5 Hz to 6,000 Hz +0, -3 dB |
| Minimum target size |
9.5 mm (0.375 in) diameter |
| Leadwire length (max) |
3 meters (10 feet) |
| Signal defeat (Not OK) |
Output <3.6 mA within 100 µs; restored in 2-3 seconds |
Application Examples
The Bently Nevada 990-04-70-03-01 is suited for monitoring vibration on pumps, compressors, turbines, and fans. In a refinery, replacing older transmitters with this module improves accuracy and reduces false trips. Its fast signal defeat response (output drops below 3.6 mA within 100 µs) protects machinery by indicating fault conditions immediately.
For power generation, the 990-04-70-03-01 provides precise 4-20 mA output proportional to 0-4 mils peak-to-peak displacement. This allows seamless integration with existing PLC and DCS systems.
Installation & Setup Guidance
Mount the Bently Nevada 990-04-70-03-01 using the included DIN clips and screws. Ensure the probe gap is set between 0.5 and 1.75 mm from the target to guarantee full-scale range. Use a shielded cable for the Proximitor Sensor output, keeping the BNC cable length under 3 meters. Power the transmitter with +12 to +35 Vdc, observing polarity. After installation, perform a zero and span adjustment using the non-interacting external adjustments.
Maintenance & Reliability
The Bently Nevada 990-04-70-03-01 requires minimal routine checks. Periodically verify the loop power remains within +12 to +35 Vdc and clean the probe face to maintain accuracy. The robust current limiting (23 mA typical) protects against overcurrent events. The CSA Division 2 rating ensures safe operation in hazardous environments.
Selection Guide & Purchasing Advice
Before purchasing, verify that your existing system accepts a 4-20 mA input and can accommodate the 990-04-70-03-01's full-scale option of 0-4 mils pp. Confirm the system length option of 7.0 meters matches your probe-to-transmitter distance. If you need assistance, contact the team at ubest101 for expert guidance on compatibility and accessories. The Bently Nevada 990-04-70-03-01 is available from PLC Source PRO, your trusted source for industrial automation parts.