Bently Nevada 990 Vibration Transmitter
Provides a 4-20 mA signal proportional to relative vibration on smaller, non-critical machinery.
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Some models in stock. View available part numbers.
Overview
Features
- Integrated Proximitor Sensor requires no external unit
- Non-isolated “PROX OUT" and "COM" terminals plus a coaxial connector to provide a dynamic vibration and gap voltage signal output for diagnostics
- Non-interacting zero and span potentiometers under the Transmitter label supports loop adjustment
- Test Input pin for quick verification of loop signal output, using a function generator as the input
- A Power-up Inhibit circuit eliminates signal errors due to line voltage transients
- A Not OK/Signal Defeat circuit prevents high outputs or false alarms due to a faulty proximity probe or loose connection
- Choice of DIN-rail clips or bulkhead mounting screws as standard options simplifies mounting
- Potted construction for high humidity (up to 100% condensing) environments
- Compatibility with 3300 NSv proximity probe allows transducer installation in small areas with minimal clearance, typical of centrifugal air compressors
Description
The Bently Nevada 990 Vibration Transmitter is intended primarily for the original equipment manufacturers (OEMs) of centrifugal air compressors or small pumps, motors, or fans who prefer to provide a simple 4 to 20 mA proportional vibration signal as the input to their machinery control system.
The 990 vibration transmitter is a 2-wire, loop-powered device that accepts input from Bently Nevada's 3300 NSv proximity probes and a matching extension cable (available in 5 m and 7 m system length options). The transmitter conditions the signal into appropriate peak-to-peak vibration amplitude engineering units, and provides this value as a proportional 4 to 20 mA industry-standard signal as the input to the control system where machinery protection alarming and logic occurs.
Bently Nevada 990 Vibration Transmitter Specifications | |
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Input | Accepts 1 non-contacting 3300 NSv Proximity Probe and extension cable |
Power | Requires +12 to +35 Vdc input at the transmitter terminal |
Signal Output | 4-20 mA |
Loop Accuracy | Within ±1.5% over specified full-scale range |
Probe Gap | Probe must be gapped between 0.5 and 1.75 mm from target to ensure full scale range |
Maximum Loop Resistance | 1,000 Ω including cable at 35 Vdc |
Current Limiting | 23 mA typical |
Zero and Span | Non-interacting external adjustments |
NOT OK/Signal Defeat | Signal output will go to less than 3.6 mA within 100 μs after a Not OK condition occurs. Signal output is restored within 2-3 seconds after the Not OK condition is removed |
Power-up Inhibit | Signal output stays at less than 3.6 mA for 2 to 3 seconds after power is applied |
Proximitor Sensor Output | Compatible with ungrounded, portable test equipment. When using grounded, ac-powered test equipment, use the 122115-01 Test Adapter for signal isolation |
Output Impedance | Prox Out has a 10 kΩ output impedance calibrated for a 10 MΩ load |
Prox Out Linear Range | 1.4 mm. Begins at approximately 0.25 mm from target surface |
Prox Out Incremental Scale Factor | 7.87 mV/μm (200 mV/mil) ± 6.5% typical including interchangeability errors when measured in increments of 0.25 mm over the linear range using a flat 30 mm target. Worst case 7.87 mV/μm ± 10%. Typical Noise Level: 50 mV/pp |
Temperature Stability | Incremental scale factor remains within ±10% of 7.87 mV/μm from 0 °C to +70 °C |
Frequency Response | 5 Hz to 6,000 Hz +0, -3 dB |
Minimum Target Size | 9.5 mm diameter |
Leadwire Length | Maximum for Proximitor Sensor Output (BNC connector), maximum cable distance is 3 meters |
Electrical Classification | General Purpose Approval by Canadian Standards Association (CSA/NRTL/C) in North America and by VDE in Europe. 990 has the CE mark for Europe |
Documents
Accessories
Required Components
These additional components are required for the operation of your product. We strongly advise you to purchase these components unless you already own them or own a suitable alternative.
Accessories
Please consider these optional accessories.
Applications
This product can be used in the following applications:
In Stock
Part Number | Price | Available | |
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990-05-50-01-00 |
Call for pricing | 13 in stock | |
990-05-50-01-05 |
Call for pricing | 5 in stock | |
990-04-70-02-00 |
Call for pricing | 1 in stock |
Interested in Other Part Numbers?
Other part numbers are available to order but are not currently in stock. Current availability for non-stock parts is "Call for availability". Click here to select options
Need Help? Call a Calibration engineer at 1-800-884-4967
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