Product Introduction
When axial thrust monitoring is critical for turbine protection, the Bently Nevada 991-06-70-02-05 Thrust Transmitter provides precise 4-20 mA output. This industrial automation module from Bently Nevada, model 991-06-70-02-05, is a probe vibration transmitter designed for axial displacement measurement. It accepts one non-contacting 3300 NSv proximity probe and extension cable, converting probe gap into a linear 4-20 mA signal.
Technical Specifications Breakdown
The Bently Nevada 991-06-70-02-05 Thrust Transmitter features the following key specifications:
| Parameter |
Value |
| Power Supply |
+12 to +35 Vdc at transmitter terminal |
| Output Signal |
4-20 mA (2-wire) |
| 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 |
| Accuracy |
±1.5% over full scale (typical) |
| Maximum Loop Resistance |
1,000 Ω including cable at 35 Vdc |
| Current Limiting |
23 mA typical |
| Not OK/Signal Defeat |
Output <3.6 mA within 100 µs; restored within 0.1 s |
| Operating Temperature |
-35°C to +85°C |
| Storage Temperature |
-51°C to +100°C |
| Weight |
0.43 kg (0.9 lbm) |
| Mounting |
DIN rail |
Ordering configuration includes full-scale option -06 (0.6-0-0.6 mm), system length -70 (7.0 meters), mounting 02 (bulkhead screws), and agency approval 05 (CSA Division 2, ATEX Zone 0/2, ABS maritime).
Industry Applications
The Bently Nevada 991-06-70-02-05 Thrust Transmitter is ideal for axial position monitoring in steam turbines, gas turbines, compressors, and large rotating machinery. It provides early warning of thrust bearing wear, helping prevent catastrophic failures. The 4-20 mA output integrates directly with PLCs, DCS, and vibration monitoring systems.
Installation & Setup Guidance
Mount the Bently Nevada 991-06-70-02-05 on a DIN rail. Connect a compatible 3300 NSv proximity probe and extension cable to the input. Wire the transmitter in a 2-wire configuration for 4-20 mA output. Power the unit with +12 to +35 Vdc. Adjust zero and span using the non-interacting external adjustments. Verify the Not OK signal defeat function by simulating a probe fault.
Troubleshooting & Common Issues
If the output drops below 3.6 mA, check for a Not OK condition such as probe damage or power loss. The transmitter restores output within 0.1 seconds after fault removal. Ensure loop resistance does not exceed 1,000 Ω. Verify power supply voltage is within range. The current limiting of 23 mA protects the loop.