Product Overview
The Bently Nevada 991-06-70-02-01 Probe Vibration Transmitter is an industrial automation module designed for accurate axial position monitoring in rotating machinery. This device accepts a non-contacting 3300 NSv proximity probe and provides a 4-20 mA output proportional to the measured thrust. With a linear range suitable for 0.6-0-0.6 mm or 25-0-25 mils, it delivers reliable performance in critical applications. A key failure-mode feature is the Not OK signal defeat, which forces the output below 3.6 mA within 100 µs upon detecting a fault, ensuring downstream safety systems respond promptly.
Technical Specifications
| Parameter |
Value |
| Output Signal |
4-20 mA |
| Power Supply |
+12 to +35 Vdc |
| Loop Accuracy |
±1.5% of full scale (typical) |
| Max Loop Resistance |
1,000 Ω at 35 Vdc |
| Current Limiting |
23 mA typical |
| Linear Range (Prox Out) |
0.25 to 1.65 mm |
| Operating Temperature |
-35°C to +85°C |
| Storage Temperature |
-51°C to +100°C |
| Weight |
0.43 kg (0.9 lb) |
These specifications are directly from the Bently Nevada 991-06-70-02-01 datasheet and ensure precise vibration monitoring in harsh environments.
Industry Applications
The Bently Nevada 991-06-70-02-01 is ideal for axial thrust monitoring in steam turbines, compressors, and large centrifugal pumps. Its robust design withstands extreme temperatures and provides a 4-20 mA signal directly to PLCs or DCS systems. The Not OK signal defeat feature makes it suitable for safety-critical installations where immediate fault indication is required.
Installation and Setup
Mount the Bently Nevada 991-06-70-02-01 on a DIN rail and connect a compatible 3300 NSv proximity probe via extension cable. Wire the transmitter in a 2-wire 4-20 mA loop with a power supply between +12 and +35 Vdc. Use non-interacting external adjustments for zero and span. Ensure the bulkhead mounting option (Option 02) is correctly secured with screws. For optimal performance, maintain loop resistance below 1,000 Ω.
Troubleshooting and Common Issues
A common failure scenario is loss of probe signal. The Bently Nevada 991-06-70-02-01 handles this by driving the output below 3.6 mA within 100 µs. If the output remains high, check wiring and probe integrity. The current limiter (23 mA typical) prevents overload. For zero drift, use the external adjustments to recalibrate. Always verify the full-scale option (-06 for 0.6 mm) matches your application requirements.
Selection Guide
When ordering the Bently Nevada 991-06-70-02-01, confirm the system length option (-70 for 7.0 meters) and mounting option (02 bulkhead screws). Ensure your system's linear range matches the -06 full-scale option (0.6-0-0.6 mm). For reliable supply, contact PLC Source PRO at ubest101.myshopify.com. Always check agency approval (CSA Div 2) for hazardous environments.