Product Introduction
When unplanned machinery downtime threatens production targets, the Bently Nevada 990-08-50-02-00 990 Vibration Transmitter delivers precise, real-time vibration data. This compact transmitter converts proximity probe signals into a linear 4-20 mA output, enabling continuous monitoring of rotating equipment. Designed for non-hazardous and Zone 2/Div 2 areas, the 990-08-50-02-00 integrates seamlessly into existing control systems.
Part of the trusted Bently Nevada 990 series, this unit is built in the USA and configured with a full-scale range of 0-8 mils pp (0-200 μm pp), a 5.0 meter system length, and bulkhead screw mounting. The 990-08-50-02-00 accepts one non-contacting 3300 NSv Proximity Probe and extension cable, making it ideal for critical asset protection.
Technical Specifications Breakdown
The 990-08-50-02-00 offers robust performance specifications, each chosen for reliability in industrial environments. Below are the key parameters provided:
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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 Output: Linear over specified full-scale range in a 2-wire configuration.
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Loop Accuracy: Within ±1.5% over full-scale range, with error in addition to Prox Out Incremental Scale Factor.
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Probe Gap: Must be gapped between 0.5 and 1.75 mm (20-55 mils) from target for full scale range.
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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 below 3.6 mA within 100 µs after a Not OK condition; restored within 2-3 seconds after removal.
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Weight: 0.43 kg (0.9 lbm).
These specifications enable the 990-08-50-02-00 to provide accurate, fast-response vibration data even in demanding conditions.
Application Spotlight
The 990-08-50-02-00 excels in monitoring critical rotating assets such as turbines, compressors, and pumps. For example, in a petrochemical plant, early detection of shaft vibration prevents catastrophic failures. The transmitter’s 5 Hz to 6,000 Hz frequency response captures both low-speed and high-speed vibration events, while the fast-acting NOT OK signal defeat alerts operators instantly to probe faults. This direct integration with DCS/PLC systems reduces maintenance costs and unplanned downtime—a clear return on investment.
In another scenario, a paper mill uses the 990-08-50-02-00 to monitor dryer rolls. The ±1.5% loop accuracy ensures reliable trend data, enabling predictive maintenance schedules. The choice of a 0-8 mils pp range matches typical vibration levels in such machinery, avoiding over-ranging and providing optimal resolution.
Installation & Setup Guidance
Proper installation ensures the 990-08-50-02-00 performs as expected. Mount the transmitter using the bulkhead screws (option 02) in a location free from excessive heat or moisture. Connect a 3300 NSv Proximity Probe and extension cable to the input. Ensure the probe gap is set between 0.5 mm and 1.75 mm from the target surface. Power the transmitter via a +12 to +35 Vdc supply, observing polarity. For the 4-20 mA loop, use a maximum loop resistance of 1,000 Ω. The BNC connector output distance should not exceed 3 meters (10 feet) to maintain signal integrity.
After wiring, adjust the non-interacting zero and span pots externally as needed. Verify the output responds linearly over the full-scale range before placing the machine in service. If mounting in a hazardous area, confirm the power supply is limited to 28 V per the Zone 2/Div 2 rating.
Maintenance & Reliability
Routine checks on the Bently Nevada 990-08-50-02-00 involve verifying the probe gap and cleaning the connector surfaces. The transmitter’s current-limiting feature at 23 mA protects against fault conditions, while the ±1.5% loop accuracy remains stable over time. No scheduled calibration is required beyond the initial setup, but periodic loop tests ensure continued accuracy. This low-maintenance design directly supports the long-term cost-benefit: reduced inspection hours and fewer false alarms. The robust enclosure and bulkhead mounting resist vibration and shock, extending service life.
Selection Guide & Purchasing Advice
Before purchasing the 990-08-50-02-00, confirm compatibility with your existing proximity probe (3300 NSv series) and cable length requirements. Verify the full-scale option (08 = 0-8 mils pp) matches your machinery’s expected vibration amplitude. The system length option (50 = 5.0 meters) and mounting option (02 = bulkhead screws) are fixed for this part number. If your application requires a different range or cable length, explore other 990 series variants. For reliable supply, consider ubest101 as a source for genuine Bently Nevada parts—ensure the part number 990-08-50-02-00 is specified exactly to avoid substitution.