Product Introduction
The Bently Nevada 990-10-70-01-00 990 Vibration Transmitter delivers reliable vibration monitoring for critical rotating machinery. Designed as an industrial automation module, this transmitter converts proximity probe signals into a 4-20 mA output proportional to shaft vibration. With a full-scale option of 0-10 mils pp (0-250 μm pp) and a 7.0-meter system length, it integrates easily into existing monitoring systems.
Technical Specifications
The following specifications are verified for the Bently Nevada 990-10-70-01-00:
| Parameter |
Value |
| Input |
Accepts 1 non-contacting 3300 NSv Proximity Probe and extension cable |
| Power Requirement |
+12 to +35 Vdc at transmitter terminal |
| Output Signal |
4-20 mAdc (2-wire) over full-scale range |
| Loop Accuracy |
Within ±1.5% over full-scale range (from TEST signal input to voltage across 250 Ω loop resistance) |
| 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 |
0.5 to 1.75 mm (20 to 55 mils) from target |
| Minimum Target Size |
9.5 mm (0.375 in) diameter |
| Weight |
0.43 kg (0.9 lbm) |
| Mounting |
35 mm DIN rail clips |
Industry Applications
The 990-10-70-01-00 vibration transmitter excels in continuous machinery monitoring. Typical applications include monitoring shaft vibration in turbines, compressors, pumps, and fans. Its fast NOT OK/signal defeat response—output drops below 3.6 mA within 100 µs after a fault—makes it ideal for safety-critical environments like oil and gas, power generation, and petrochemical plants. The transmitter operates reliably in non-hazardous, Zone 2, or Division 2 hazardous areas when powered by a 28 V supply.
Installation & Setup Guidance
Mount the Bently Nevada 990-10-70-01-00 on a standard 35 mm DIN rail using the included clips. Connect one non-contacting 3300 NSv proximity probe and extension cable to the input. Ensure the probe gap falls between 0.5 mm and 1.75 mm from the target to achieve full-scale range. Apply a +12 to +35 Vdc supply to the transmitter terminals; the maximum loop resistance including cable is 1,000 Ω at 35 Vdc. For optimal accuracy, use a 250 Ω loop resistance during calibration.
Troubleshooting & Common Issues
The NOT OK/signal defeat feature of the 990-10-70-01-00 activates when the probe or electronics detect an anomaly. If output drops below 3.6 mA, check the probe gap and cable integrity. A signal loss lasting more than 2-3 seconds indicates a persistent issue; verify the target material and probe tip condition. For frequency response deviations outside 5–6000 Hz, inspect the proximity probe and target surface. The non-interacting zero and span adjustments simplify field recalibration.