Product Introduction
When machinery vibration monitoring demands reliability, the Bently Nevada 990-10-70-02-00 delivers precise 4-20 mA loop output for early fault detection. This 990 Vibration Transmitter accepts one non-contacting 3300 NSv Proximity Probe and extension cable, converting probe gap changes into a proportional current signal. Designed for industrial environments, the 990-10-70-02-00 is built in the USA and offers a full-scale option of 0-10 mils pp (0-250 μm pp).
Technical Specifications
| Parameter |
Value |
| Input |
Accepts 1 non-contacting 3300 NSv Proximity Probe and extension cable |
| Power Requirement |
+12 to +35 Vdc at transmitter terminal |
| Output |
4-20 mAdc over full-scale range, 2-wire |
| Loop Accuracy |
Within ±1.5% over full-scale range (at 250 Ω load, excluding probe scale factor) |
| Maximum Loop Resistance |
1,000 Ω including cable at 35 Vdc |
| Current Limiting |
23 mA typical |
| Frequency Response |
5 Hz to 6,000 Hz +0, -3 dB |
| Probe Gap Range |
0.5 to 1.75 mm (20 to 55 mils) |
| Minimum Target Size |
9.5 mm (0.375 in) diameter |
| NOT OK/Signal Defeat |
Output <3.6 mA within 100 μs; restores 2-3 seconds after condition removed |
| Weight |
0.43 kg (0.9 lbm) |
| Hazardous Area Approval |
Non-Hazardous, Zone 2 or Div 2 (Power Supply: 28 V) |
Industry Applications
The Bently Nevada 990-10-70-02-00 is ideal for monitoring critical rotating machinery such as steam turbines, centrifugal compressors, and large pumps. Its 4-20 mA loop integrates seamlessly with PLCs and DCSs for continuous vibration surveillance. For example, in a turbine train, the transmitter detects shaft relative vibration, triggering alarms before damage occurs. The fast NOT OK response (<100 μs) ensures safety during sensor faults.
Installation & Setup Guidance
Proper installation of the Bently Nevada 990-10-70-02-00 is essential for accurate operation. Mount the transmitter using bulkhead screws (mounting option 02). Connect the non-contacting 3300 NSv probe and extension cable; ensure the probe gap is between 0.5 and 1.75 mm from the target. The system length option 70 provides a 7.0-meter (23.0-foot) cable. Use the BNC connector for Proximitor Sensor output, with maximum cable distance of 3 meters (10 feet). Power the transmitter with +12 to +35 Vdc at the terminal. Adjust zero and span via non-interacting external adjustments.
Maintenance & Reliability
The 990-10-70-02-00 design minimizes maintenance through its signal defeat feature. The output drops below 3.6 mA within 100 μs of a Not OK condition, and restores within 2-3 seconds after removal. This prevents false alarms and ensures system reliability. Periodically inspect the probe gap and cable connections. The transmitter's current limiting (23 mA typical) protects against loop faults. Routine checks of the 4-20 mA loop accuracy (within ±1.5%) validate performance.
Selection Guide & Purchasing Advice
Before purchasing the Bently Nevada 990-10-70-02-00, confirm the full-scale option (10 = 0-10 mils pp), system length (70 = 7.0 meters), mounting option (02 = bulkhead screws), and agency approval (00 = not required). Verify compatibility with your existing 3300 NSv probes and extension cables. For reliable supply and technical support, contact PLC Source PRO (ubest101). Ensure your power supply delivers +12 to +35 Vdc and loop resistance does not exceed 1,000 Ω.