The Bently Nevada 990-08-70-01-00 converts shaft vibration into a standard 4-20 mA industrial signal. Many facilities rely on this transmitter for continuous monitoring of turbines, compressors, and fans. It works with a single non-contacting 3300 NSv proximity probe and extension cable.
Specifically, this model uses full-scale option 08, which covers 0-8 mils pp (0-200 μm pp). The system length option 70 gives you a 7.0 meter (23.0 feet) total cable length. Mounting option 01 includes 35 mm DIN rail clips for quick panel installation.
Additionally, the 990 transmitter operates from a +12 to +35 Vdc loop power supply. You do not need a separate power source. The device provides a true 4-20 mA output in a 2-wire configuration.
Input and Output
Input: Accepts 1 non-contacting 3300 NSv proximity probe
Output: 4-20 mAdc over specified full-scale range
Loop accuracy: Within ±1.5% of full scale (measured across 250 Ω load)
Note: The ±1.5% error adds to the Prox Out Incremental Scale Factor
Electrical Ratings
Power requirement: +12 to +35 Vdc at transmitter terminals
Maximum loop resistance: 1,000 Ω including cable at 35 Vdc
Current limiting: 23 mA typical
Frequency and Response
Frequency response: 5 Hz to 6,000 Hz +0, -3 dB
NOT OK signal defeat: Output drops below 3.6 mA within 100 µs after a fault
Recovery time: Signal restores within 2-3 seconds after fault clears
Probe and Target Requirements
Probe gap range: 0.5 to 1.75 mm (20 to 55 mils) from target
Minimum target size: 9.5 mm (0.375 in) diameter
Leadwire length max: 3 meters (10 feet) for Proximitor sensor output with BNC connector
The Bently Nevada 990-08-70-01-00 includes non-interacting external adjustments for zero and span. This means you can set one without affecting the other. Consequently, calibration becomes much faster and more straightforward.
The transmitter weighs only 0.43 kg (0.9 lbm). Its small size fits easily inside control panels or junction boxes. Mounting option 01 provides 35 mm DIN rail clips for secure attachment.
Furthermore, this unit carries agency approval option 00, meaning no specific approvals are required. It suits non-hazardous locations only. For Zone 2 or Division 2 areas, choose a model with the appropriate approval code.
The Bently Nevada 990 series is made in the U.S.A. It does not require any external power supply beyond the loop power.
First, mount the transmitter on a 35 mm DIN rail using the supplied clips. Next, connect your 3300 NSv proximity probe and the 7.0 meter extension cable. Then, wire the loop power supply (+12 to +35 Vdc) to the transmitter terminals.
After powering up, gap the probe correctly between 0.5 and 1.75 mm from the target. This step is critical for accurate full-scale operation. Finally, use the external zero and span potentiometers to calibrate the 4-20 mA output.
For best results, keep the Proximitor sensor output cable (BNC connection) under 3 meters (10 feet). This prevents signal degradation.
Bently Nevada 990-08-70-01-00 transmitter (1 unit)
35 mm DIN rail clips for mounting
Quick start reference guide
Note: The proximity probe and extension cable are sold separately. No calibration certificate or warranty statement is included.
All orders ship via FedEx, UPS, or DHL. Tracking numbers are provided upon dispatch.
1. What is the full-scale vibration range of the 990-08-70-01-00?
The full-scale range is 0-8 mils pp (0-200 μm pp). Option code “08” in the model number identifies this range.
2. Can I use this transmitter in a hazardous area?
No. Agency approval option “00” means no hazardous area certifications. This model is for non-hazardous locations only. For Zone 2 or Division 2, select a Bently Nevada 990 with approval option “CN” or other certified codes.
3. How long is the system cable for this model?
System length option “70” provides a 7.0 meter (23.0 feet) total cable length, including the probe and extension cable.
4. What happens if the proximity probe fails or disconnects?
The NOT OK signal defeat activates immediately. Output current drops below 3.6 mA within 100 µs. Once the fault clears, the output returns to normal within 2-3 seconds.
5. What loop resistance can I use with a 24 Vdc power supply?
Use this formula: (Supply voltage - 12V) / 0.02A = maximum resistance. For 24 Vdc: (24-12)/0.02 = 600 Ω. At 35 Vdc, you can use up to 1,000 Ω including cable resistance.
| Brand Name | Bently Nevada |
| Model No. | 990-08-70-01-00 |
| Product Type | Vibration Transmitter |
| hasMerchantReturnPolicy | Adjust according to reality |
| Shippingdetails | Adjust according to reality |
