Bently Nevada 990-08-70-02-00 - Vibration Transmitter

Bently Nevada 990-08-70-02-00 Vibration Transmitter

Robust Vibration Monitoring with Bulkhead Mounting

The Bently Nevada 990-08-70-02-00 converts shaft relative vibration into a standard 4-20 mA industrial signal. Plants use this transmitter for continuous monitoring of rotating machinery like turbines, compressors, and pumps. It works seamlessly with one non-contacting 3300 NSv proximity probe and an extension cable.

Specifically, full-scale option 08 delivers a 0-8 mils pp (0-200 μm pp) measurement range. System length option 70 provides a 7.0 meter (23.0 feet) total cable length. Mounting option 02 includes bulkhead screws for a rigid, permanent installation.

Additionally, the 990 transmitter operates from a +12 to +35 Vdc loop power supply. You do not need any separate power source. The device produces a true 4-20 mA output in a standard 2-wire configuration.

Detailed Technical Specifications

Input and Output Characteristics

• Input: Accepts 1 non-contacting 3300 NSv proximity probe

• Output: 4-20 mAdc over the specified full-scale range

• Loop accuracy: Within ±1.5% of full scale

• Test condition: Accuracy measured from TEST signal input to voltage across a 250 Ω load

• Important: The ±1.5% error adds to the Prox Out Incremental Scale Factor

Electrical Ratings

• Power requirement: +12 to +35 Vdc at the transmitter terminals

• Maximum loop resistance: 1,000 Ω including all cable at 35 Vdc

• Current limiting: 23 mA typical

Frequency Response and Fault Handling

• 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 automatically restores within 2-3 seconds after fault clears

Probe and Target Specifications

• Probe gap range: Must be between 0.5 and 1.75 mm (20 and 55 mils) from target

• Minimum target size: 9.5 mm (0.375 in) diameter

• Leadwire length maximum: 3 meters (10 feet) for Proximitor sensor output with BNC connector

External Adjustments for Zero and Span

The Bently Nevada 990-08-70-02-00 features non-interacting external adjustments for zero and span. This design lets you set each parameter independently. Therefore, calibration becomes much faster and more precise without repetitive tweaking.

Mechanical Information and Mounting Details

This transmitter weighs only 0.43 kg (0.9 lbm). Its compact size fits easily inside control panels, junction boxes, or small enclosures. Mounting option 02 uses bulkhead screws. These screws provide a strong, vibration-resistant attachment method.

Furthermore, agency approval option 00 means no specific certifications are required. Use this model only in non-hazardous locations. For Zone 2 or Division 2 hazardous areas, select a Bently Nevada 990 with approval codes like CN or other certified options.

The 990 series is proudly made in the U.S.A. It requires no external power supply beyond the loop power itself.

Installation Guidelines

First, mount the transmitter using the supplied bulkhead screws. Choose a flat, stable surface near your monitoring equipment. 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 gap setting is essential for accurate full-scale operation.

Finally, use the external zero and span potentiometers to calibrate the 4-20 mA output. For best signal quality, keep the Proximitor sensor output cable (BNC connection) under 3 meters (10 feet).

Packaging List

• Bently Nevada 990-08-70-02-00 transmitter (1 unit)

• Bulkhead screws for mounting (option 02 hardware kit)

• Basic installation instruction sheet

Note: The 3300 NSv proximity probe and extension cable are sold separately. No calibration certificate or warranty statement is included in this package.

Shipping Information

All orders ship via FedEx, UPS, or DHL. Tracking information is provided after dispatch.

Frequently Asked Questions (FAQ)

1. What is the full-scale vibration range of the 990-08-70-02-00?
The full-scale range is 0-8 mils pp (0-200 μm pp). Option code “08” in the model number identifies this specific range.

2. How is mounting option 02 different from option 01?
Mounting option 02 uses bulkhead screws for permanent screw-mounted installation. Option 01 uses 35 mm DIN rail clips. The 990-08-70-02-00 is ideal when you cannot use DIN rails.

3. Can I use this transmitter in a hazardous area?
No. Agency approval option “00” means no hazardous area certifications. This model is restricted to non-hazardous locations only. For Zone 2 or Division 2 areas, choose a Bently Nevada 990 with approval option “CN” or other certified codes.

4. How long is the system cable for this model?
System length option “70” provides a 7.0 meter (23.0 feet) total cable length. This length includes both the probe and the extension cable assembly.

5. What happens if the proximity probe fails or gets disconnected?
The NOT OK signal defeat activates immediately. Output current drops below 3.6 mA within 100 µs. After you fix the fault, the output returns to normal operation within 2-3 seconds.