Product Overview
In axial thrust monitoring applications, the Bently Nevada 991-25-70-03-00 probe vibration transmitter delivers precise 4-20 mA signals for critical machinery protection. This industrial automation module converts proximity probe measurements into a current loop output, enabling real-time assessment of thrust bearing condition. Designed for use with 3300 NSv proximity probes, the 991-25-70-03-00 ensures accurate and reliable operation in demanding environments.
Technical Specifications
| Parameter |
Specification |
| Full-Scale Option |
25-0-25 mils (0.6-0-0.6 mm) |
| Output Signal |
4-20 mA (two-wire) |
| Accuracy |
Within ±1.5% of full scale (typical) |
| Power Input |
+12 to +35 Vdc at transmitter terminal |
| Maximum Loop Resistance |
1,000 Ω at 35 Vdc |
| Current Limiting |
23 mA typical |
| Not OK Signal |
<3.6 mA within 100 µs |
| Operating Temperature |
-35°C to +85°C (-31°F to +185°F) |
| Storage Temperature |
-51°C to +100°C (-60°F to +212°F) |
| Weight |
0.43 kg (0.9 lbm) |
| Linear Range |
0.25 to 1.65 mm for Prox Out. Suitable for 0.6-0-0.6 mm or 25-0-25 mils current loop linear ranges |
Industry Applications
The Bently Nevada 991-25-70-03-00 is ideal for axial thrust monitoring in steam turbines, gas turbines, and centrifugal compressors. Its 4-20 mA output integrates directly with distributed control systems (DCS) and programmable logic controllers (PLCs), providing continuous thrust bearing condition data. The transmitter is particularly effective in applications requiring early detection of thrust bearing wear or misalignment, helping to prevent costly unplanned downtime.
Installation & Setup
Mount the Bently Nevada 991-25-70-03-00 using DIN clips and screws (Mounting Option 03). Connect a 3300 NSv proximity probe and extension cable to the input. Supply +12 to +35 Vdc power at the transmitter terminal. The zero and span adjustments are non-interacting and externally accessible, simplifying calibration. Ensure the loop resistance does not exceed 1,000 Ω at 35 Vdc to maintain accuracy.
Compatible Systems
This transmitter works with Bently Nevada 3300 NSv proximity probes and any control system that accepts a 4-20 mA input. Typical integration includes Bently Nevada 3500 monitoring systems, Allen-Bradley ControlLogix, Siemens S7, and third-party DCS platforms. The Not OK function provides immediate fault indication by dropping the output below 3.6 mA within 100 µs of a detected fault.
Selection Guide & Purchasing Advice
When ordering the 991-25-70-03-00, verify the full-scale option (25-0-25 mils), system length (7.0 meters), mounting option (DIN clips), and agency approval (not required). For reliable sourcing and expert support, contact ubest101 to confirm stock and lead times. Proper selection ensures optimal performance in your specific axial thrust monitoring application.