Bently Nevada 990-04-70-01-00 Vibration Transmitter
A 0–4 mil peak-to-peak, 7 m 3300 NSv vibration transmitter with DIN-rail mounting and no approval option.
Product Identification
990-04-70-01-00 is a two-wire, loop-powered Bently Nevada vibration transmitter for one 3300 NSv probe and extension-cable system. It converts peak-to-peak vibration into a proportional 4–20 mA signal for the machinery control system.
The order code selects a 0–4 mil peak-to-peak full scale, 7.0 m transducer system length, 35 mm DIN-rail clips and no agency approval requirement.
Engineering Data
| Manufacturer | Bently Nevada, a Baker Hughes business |
|---|---|
| Complete Model | 990-04-70-01-00 |
| Input System | One 3300 NSv probe and extension cable |
| Full Scale | 0–4 mil peak-to-peak (0–100 μm) |
| System Length | 7.0 m |
| Mounting | 35 mm DIN-rail clips |
| Approval Option | Not required |
| Output | Two-wire 4–20 mA proportional vibration signal |
| Loop Accuracy | ±1.5% of specified full scale |
| Probe Gap Range | 0.5 to 1.75 mm |
| Power Supply | 17 to 35 VDC |
| Maximum Loop Resistance | 1,000 Ω at 35 VDC |
| Not-OK Response | Output below 3.6 mA after detected probe fault |
Functions
- Integrates Proximitor signal conditioning into the transmitter assembly.
- Provides PROX OUT and COM access plus a coaxial diagnostic connector.
- Uses independent zero and span adjustments for loop calibration.
- Suppresses misleading high loop output when the probe is faulty or disconnected.
Applications
- OEM centrifugal compressor vibration transmission.
- Small pump, motor and fan vibration input to plant control systems.
- Compact installations requiring one proximity channel and a 4–20 mA interface.
Lifecycle
- Keep the probe and extension-cable identities with the transmitter record.
- Trend loop zero, span and gap values to support maintenance diagnosis.
- Retain the approved test-adapter and calibration procedure with the spare strategy.
FAQ
Which probe system belongs with 990-04-70-01-00?
Use one compatible 3300 NSv probe and extension cable totaling the specified seven-metre system length; other proximity families are not automatically interchangeable.
Can 990-04-70-01-00 be substituted with a 5 m transmitter?
Not without redesigning the matched probe-and-cable chain. System length is part of the calibrated transducer configuration.
What DCS scaling is required for 990-04-70-01-00?
The control-system input must map the 4–20 mA signal to the selected 0–4 mil peak-to-peak range and handle the below-3.6 mA Not-OK state.
Why is the 990/991 test adapter relevant to 990-04-70-01-00?
The diagnostic signal is not isolated from the loop; the recommended adapter preserves isolation and correct signal polarity when using powered test equipment.
Does 990-04-70-01-00 include hazardous-area approvals?
No. The final 00 field selects no approval option, so classified installations require the appropriate certified execution.
What should be recorded before replacing 990-04-70-01-00?
Capture probe and extension-cable numbers, gap voltage, loop supply and resistance, DCS scaling, zero/span settings and mounting details.
