Product Introduction
When unexpected machinery vibration threatens production uptime, the Bently Nevada 990-04-70-03-CN provides accurate, real-time vibration monitoring. This 990 Vibration Transmitter accepts one non-contacting 3300 NSv Proximity Probe and extension cable, converting vibration into a 4-20 mAdc signal. The 990-04-70-03-CN is designed for continuous condition monitoring in industrial environments, helping detect developing faults before they cause catastrophic failure.
Technical Specifications
| Parameter |
Value |
| Full-scale Option |
04: 0-4 mils pp (0-100 μm pp) |
| System Length Option |
70: 7.0 meters (23.0 feet) |
| Mounting Option |
03: DIN clips and screws |
| Power Requirement |
+12 to +35 Vdc at transmitter terminal |
| Maximum Loop Resistance |
1,000 Ω including cable at 35 Vdc |
| Current Limiting |
23 mA typical |
| Transmitter Weight |
0.43 kg (0.9 lbm) |
| 4-20 mA Loop Accuracy |
Within ±1.5% over specified full-scale range |
| Frequency Response |
5 Hz to 6,000 Hz +0, -3 dB |
| Probe Gap Range |
0.5 to 1.75 mm (20 to 55 mils) |
| NOT OK/Signal Defeat |
Output goes below 3.6 mA within 100 µs after Not OK condition |
Industry Applications
The Bently Nevada 990-04-70-03-CN excels in rotating machinery protection. Typical applications include monitoring sleeve bearing vibration in pumps, compressors, turbines, and fans. In a petrochemical plant, early detection of shaft vibration using the 990-04-70-03-CN prevented a unplanned shutdown by alerting operators to a developing imbalance. Its 4-20 mA output integrates directly with PLCs and DCS systems for seamless alarm and trip logic.
Installation & Setup Guidance
When installing the Bently Nevada 990-04-70-03-CN, ensure the probe is gapped between 0.5 and 1.75 mm from the target to guarantee full-scale range. Use the supplied DIN clips and screws for secure mounting. The power supply must provide +12 to +35 Vdc at the transmitter terminal. For Proximitor Sensor Output via BNC connector, keep cable distance under 3 meters (10 feet). The zero and span adjustments are non-interacting, simplifying calibration.
Troubleshooting & Common Issues
A common issue with vibration transmitters is signal loss due to improper gap setting. The 990-04-70-03-CN includes NOT OK/signal defeat functionality: if a fault occurs (e.g., probe damage), the output drops below 3.6 mA within 100 µs, providing a definite diagnostic indicator. After the fault clears, output restores within 2-3 seconds. If readings appear erratic, verify loop resistance does not exceed 1,000 Ω. Current limiting at 23 mA typical prevents damage from short circuits.
Maintenance & Reliability
For long-term reliability, periodically inspect the probe face for contamination and verify cable integrity. The 990-04-70-03-CN operates in non-hazardous, Zone 2, or Div 2 hazardous area locations with a 28 V power supply. Routine checks of the 4-20 mA loop accuracy against a calibrated reference ensure measurement integrity. Its compact design (0.43 kg) and rugged construction minimize maintenance needs, reducing total cost of ownership.
Buying Guide
Before purchasing the Bently Nevada 990-04-70-03-CN, confirm compatibility with your existing 3300 NSv probe and extension cable. Verify the full-scale range (0-4 mils pp) matches your application. For reliable sourcing, trust ubest101 as your industrial automation parts supplier. They provide genuine, factory-sealed modules backed by quality assurance.