Product Overview
When machinery vibration exceeds safe limits, the Bently Nevada 990-04-70-03-05 990 Vibration Transmitter provides continuous, accurate monitoring. This industrial automation module accepts one non-contacting 3300 NSv proximity probe and delivers a 4-20 mA signal proportional to vibration amplitude. Designed for hazardous areas with CSA Division 2, ATEX Zone 0, and ATEX Zone 2 approvals, it ensures reliable operation in demanding environments.
Technical Specifications
The Bently Nevada 990-04-70-03-05 offers precise measurement over a full-scale range of 0-4 mils pp (0-100 μm pp) with an accuracy within ±1.5% (in addition to probe scale factor). Key parameters include:
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Input: Accepts 1 non-contacting 3300 NSv probe and extension cable
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Power: Requires +12 to +35 Vdc input at transmitter terminal
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Output: 4 to 20 mAdc over specified full-scale range in 2-wire configuration
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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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Weight: 0.43 kg (0.9 lbm)
The probe must be gapped between 0.5 and 1.75 mm (20 to 55 mils) from the target to ensure full-scale range. Zero and span adjustments are non-interacting external adjustments.
Industry Applications
In rotating machinery applications such as turbines, compressors, and pumps, the Bently Nevada 990-04-70-03-05 delivers real-time vibration data for predictive maintenance. Its fast NOT OK/signal defeat function – output drops below 3.6 mA within 100 µs after a fault – enables immediate shutdown or alarm activation, preventing catastrophic failures. The 7.0-meter (23.0 feet) system length option suits installations with remote probe placement.
Installation & Setup Guidance
Mount the Bently Nevada 990-04-70-03-05 using DIN clips and screws (mounting option 03). Ensure the proximity probe is correctly gapped between 0.5 and 1.75 mm from the target. Connect the 3300 NSv probe and extension cable; maximum cable distance from Proximitor Sensor Output (BNC connector) is 3 meters (10 feet). Power the transmitter with +12 to +35 Vdc, and verify loop resistance does not exceed 1,000 Ω at 35 Vdc.
Troubleshooting & Common Issues
A key failure mode in vibration transmitters is loss of signal due to probe gap drift or cable faults. The Bently Nevada 990-04-70-03-05 addresses this with its NOT OK/signal defeat feature: within 100 µs of a Not OK condition, the output drops below 3.6 mA. Output restores automatically within 2-3 seconds after the fault clears. For accurate readings, verify probe gap regularly and ensure cable connections are secure. If output is out of range, check power supply (must be +12 to +35 Vdc) and loop resistance.
Buying Guide
Before purchasing the Bently Nevada 990-04-70-03-05, confirm your system requirements: full-scale option 04 (0-4 mils pp), system length 7.0 meters, and mounting option 03 (DIN clips and screws). This unit includes agency approvals for CSA Division 2, ATEX Zone 0, ATEX Zone 2, and ABS maritime. For reliable supply, contact PLC Source PRO (store link: ubest101.myshopify.com) to verify stock and lead times.