The Bently Nevada 990-04-70-03-00 990 Vibration Transmitter provides reliable, real-time vibration monitoring for critical rotating machinery. Designed for hazardous environments, this industrial automation module ensures early detection of faults, reducing unplanned downtime.
Product Introduction
The Bently Nevada 990-04-70-03-00 is a 990 Vibration Transmitter that converts proximity probe signals into a 4-20 mA output. It accepts one non-contacting 3300 NSv Proximity Probe and extension cable. With a full-scale option of 0-4 mils pp (0-100 μm pp) and a 7.0-meter system length, it offers precise vibration measurement. The transmitter weighs 0.43 kg and is powered by +12 to +35 Vdc.
Technical Specifications
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Input: Accepts 1 non-contacting 3300 NSv Proximity Probe and extension cable.
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Power: Requires +12 to +35 Vdc input at the transmitter terminal.
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4-20 mA Signal Output: 4 to 20 mAdc over specified full-scale range in 2-wire configuration.
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Loop Accuracy: Within ±1.5% over specified full-scale range (additional to Prox Out Incremental Scale Factor).
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Maximum Loop Resistance: 1,000 Ω including cable at 35 Vdc.
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Current Limiting: 23 mA typical.
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Frequency Response: 5 Hz to 6,000 Hz +0, 3 dB.
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NOT OK/Signal Defeat: Output goes to less than 3.6 mA within 100 µs after Not OK; restores within 2-3 seconds after condition removed.
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Zero and Span: Non-interacting external adjustments.
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Probe Gap: Must be gapped between 0.5 and 1.75 mm (20 and 55 mils) from target.
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Minimum Target Size: 9.5 mm (0.375 in) diameter.
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Leadwire Length (Proximitor Sensor Output): Maximum 3 meters (10 feet) via BNC connector.
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Hazardous Area: Suitable for Non-Hazardous, Zone 2, or Div 2 locations (Power Supply: 28 V).
Industry Applications
The Bently Nevada 990-04-70-03-00 vibration transmitter excels in machinery protection for turbines, compressors, pumps, and fans. In a typical application, it monitors shaft vibration and alerts operators to developing faults. The fast NOT OK response (< 100 µs) ensures immediate shutdown protection, preventing catastrophic failures. Its robust 4-20 mA output integrates seamlessly with PLCs and DCS systems.
Installation & Setup
Mount the Bently Nevada 990-04-70-03-00 using DIN clips and screws (Mounting Option 03). Connect the 3300 NSv probe and extension cable with the correct leadwire length (max 3 m). Gap the probe between 0.5 and 1.75 mm from the target. Power the transmitter with +12 to +35 Vdc at the terminal. Adjust zero and span using the non-interacting external pots. Verify loop resistance does not exceed 1,000 Ω.
Troubleshooting & Common Issues
The Bently Nevada 990-04-70-03-00 includes built-in fault detection: if a probe or cable fault occurs, the output drops below 3.6 mA within 100 µs. This ensures that downstream systems detect a lost signal immediately. Common issues include incorrect probe gap or excessive loop resistance. Always verify the supply voltage is between +12 and +35 Vdc. If the signal does not restore after a fault, check the probe and cable continuity. The current limiting (23 mA typical) prevents damage to the loop.
Buying Guide
When selecting the Bently Nevada 990-04-70-03-00, confirm your full-scale range (option 04: 0-4 mils pp) and cable length (option 70: 7.0 m). Ensure your system accepts a 4-20 mA input and that the loop resistance is within limits. For expert advice, purchase from PLC Source PRO (available at ubest101.myshopify.com) – a trusted source for industrial automation spares.