Product Overview
Upgrade your thrust monitoring systems with the Bently Nevada 991-25-70-02-CN Probe Vibration Transmitter. This modern unit replaces older, less reliable transmitters, offering enhanced accuracy and robustness for axial position measurement. Designed for DIN rail mounting and accepting a 3300 NSv proximity probe, the 991-25-70-02-CN delivers a 4-20 mA output proportional to thrust. Its precise linear range and advanced signal handling ensure dependable operation in demanding environments.
Technical Specifications
| Parameter |
Value |
| Full-scale Option |
25-0-25 mils |
| System Length |
7.0 meters (23.0 feet) |
| Mounting Option |
Bulkhead screws |
| Mount |
DIN rail |
| Output Signal |
4-20 mA |
| Power Requirement |
+12 to +35 Vdc at transmitter terminals |
| Linear Range (Prox Out) |
0.25 to 1.65 mm |
| 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) |
| Input |
1 non-contacting 3300 NSv Proximity Probe and extension cable |
| 4-20 mA Loop Accuracy |
Within ±1.5% of specified full scale (typical) |
| Maximum Loop Resistance |
1,000 ohms at 35 Vdc |
| Current Limiting |
23 mA typical |
| Zero and Span |
Non-interacting external adjustments |
| Not OK/Signal Defeat |
Output <3.6 mA within 100 µs; restores within 0.1 s after condition clears |
Industry Applications
The Bently Nevada 991-25-70-02-CN is ideal for measuring axial thrust in rotating machinery, including compressors, steam turbines, gas turbines, and large pumps. Its 25-0-25 mils full-scale range suits typical thrust bearing clearances. The 4-20 mA output integrates directly with PLCs, DCS, and condition monitoring systems. Replacing older transmitters with this model upgrades system reliability and reduces unplanned downtime.
Installation and Setup
Mount the 991-25-70-02-CN on a standard DIN rail using the bulkhead screws (mounting option 02). Connect a single 3300 NSv proximity probe and extension cable to the transmitter input. Wire the 2-wire 4-20 mA loop to the control system, ensuring the supply voltage remains between +12 and +35 Vdc at the transmitter terminals. Adjust zero and span via the non-interacting external pots as needed. The Not OK signal defeat ensures fail-safe output under fault conditions.
Maintenance and Reliability
This solid-state transmitter requires minimal routine maintenance. Periodically inspect the probe and cable for damage, and verify supply voltage at the terminals. The wide operating temperature range (-35°C to +85°C) and robust construction make it suitable for harsh industrial environments. With no moving parts and built-in current limiting, the 991-25-70-02-CN provides long service life, reducing total cost of ownership compared to older designs.
Selection Guide
When ordering, specify part number 991-25-70-02-CN for the exact configuration described. Ensure compatibility with your existing 3300 NSv probe system. For reliable supply of this and other Bently Nevada spare parts, trust ubest101 as your industrial automation partner.