990-10-70-02-00 Vibration Transmitter Overview
When machinery vibration threatens uptime, the 990-10-70-02-00 from Bently Nevada delivers a precise, loop-powered solution. This 990 Vibration Transmitter accepts one non-contacting 3300 NSv Proximity Probe and extension cable, converting dynamic shaft motion into a standard 4-20 mA signal. Designed for continuous condition monitoring, it helps maintenance teams detect developing faults before they escalate.
With a full-scale range of 0-10 mils pp (0-250 μm pp), the transmitter covers typical vibration amplitudes in rotating equipment. The 7.0-meter (23.0 feet) system length option provides flexibility for probe placement. Bulkhead screw mounting simplifies installation in existing panels or junction boxes.
Key Features and Technical Specifications
Every specification of the 990-10-70-02-00 is engineered for accuracy and reliability. The table below summarizes the critical parameters.
| Parameter | Value |
|---|---|
| Input | 1 non-contacting 3300 NSv Proximity Probe and extension cable |
| Power | +12 to +35 Vdc at transmitter terminal |
| Output | 4-20 mA dc over full-scale range, 2-wire |
| Full-scale range | 0-10 mils pp (0-250 μm pp) |
| Accuracy | ±1.5% over full-scale range |
| Frequency response | 5 Hz to 6,000 Hz +0, 3 dB |
| Maximum loop resistance | 1,000 Ω including cable at 35 Vdc |
| Current limiting | 23 mA typical |
| NOT OK signal | Output < 3.6 mA within 100 µs, restores in 2-3 seconds |
| Probe gap | 0.5 to 1.75 mm (20 to 55 mils) |
| Minimum target size | 9.5 mm (0.375 in) diameter |
| Leadwire length | Max 3 meters (10 feet) for Proximitor output |
| Weight | 0.43 kg (0.9 lbm) |
| Mounting | Bulkhead screws |
The 4-20 mA loop accuracy is rated from the TEST signal input to the voltage measured across a 250 Ω loop resistance, with error in addition to the Prox Out Incremental Scale Factor. Non-interacting external zero and span adjustments simplify calibration.
Buyer's Guide: Evaluating the 990-10-70-02-00
When selecting a vibration transmitter, consider these factors:
- Input compatibility: The 990-10-70-02-00 works with 3300 NSv proximity probes, ensuring seamless integration with existing Bently Nevada systems.
- Power requirements: It accepts +12 to +35 Vdc, making it suitable for most industrial power supplies. Verify your loop voltage to ensure proper operation.
- Output signal: The 4-20 mA output is industry-standard, compatible with PLCs, DCSs, and standalone monitors.
- Environmental rating: The transmitter is rated for non-hazardous, Zone 2, or Div 2 hazardous areas. Confirm your area classification before installation.
For applications requiring high accuracy, the ±1.5% full-scale accuracy ensures reliable data. The fast NOT OK response (< 3.6 mA within 100 µs) alerts operators to probe faults quickly, minimizing downtime.
Installation and Setup
Mount the transmitter using the bulkhead screws in a location that allows easy access to zero and span adjustments. Connect the 3300 NSv probe and extension cable to the input. Wire the loop to a power supply providing +12 to +35 Vdc. Ensure the total loop resistance, including cable, does not exceed 1,000 Ω at 35 Vdc. Gap the probe between 0.5 and 1.75 mm (20 and 55 mils) from the target to achieve full-scale range. Keep the leadwire length from the Proximitor sensor output to the transmitter under 3 meters (10 feet).
Maintenance and Reliability
Regularly inspect the probe and cable for damage. Verify the output signal at zero and span points using the external adjustments. Periodically test the NOT OK function to ensure the output drops below 3.6 mA within 100 µs. Follow the manufacturer's manual for detailed procedures. The transmitter's robust design supports long service life in demanding environments.
Compatibility and Integration
The 4-20 mA output connects directly to any analog input module that accepts standard current loops. It is compatible with Bently Nevada monitoring systems and third-party PLCs/DCSs. The 2-wire configuration simplifies wiring, reducing installation cost. The 0-10 mils pp range matches many rotating machinery vibration limits.
Troubleshooting Common Issues
If the output is stuck at a low value (< 3.6 mA), check for a NOT OK condition, such as probe damage or cable fault. Verify the supply voltage is within +12 to +35 Vdc. If the output is inaccurate, recalibrate zero and span. Ensure the probe gap is within the specified range. If problems persist, consult the Bently Nevada documentation or contact AutoDCSTech.
Product Support and Availability
The 990-10-70-02-00 is available through AutoDCSTech. Please verify current lifecycle status and availability with AutoDCSTech before ordering. Our team can assist with technical questions and ordering information.
