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|
|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|
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.
Please consider these optional accessories.
This product can be used in the following applications:
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