The 991-06-XX-01-05 MOD:164113-01 is a Bently Nevada loop-powered thrust transmitter featuring an integrated Proximitor sensor. Fully compatible with 3300 NSv proximity probes, this unit works seamlessly with industrial machinery control systems to deliver reliable 4 to 20 mA proportional axial displacement monitoring and robust hazardous area protection.
High-Resolution Measurement
• Axial Displacement Range: 0.6-0-0.6 mm measurement range for precise thrust position monitoring.
• 4-20 mA Output: Industry-standard proportional signal for seamless integration with control systems.
• Diagnostic Capability: Non-isolated PROX OUT and coaxial connector provide dynamic vibration and gap voltage signals.
• Loop Adjustment: Non-interacting zero and span potentiometers under the label for accurate calibration.
• Test Input Pin: Enables quick verification of loop signal output using variable DC voltage source.
• Signal Integrity: Power-up inhibit and Not OK/Signal Defeat circuits prevent errors from transients or faulty probes.
Specific Application
- Centrifugal air compressor monitoring.
- Small industrial pump protection.
- Heavy-duty marine motor logging.
- Cooling fan alignment tracking.
- System Compatibility and Alternative Models
- System Compatibility
- Connects to 3300 NSv proximity probes.
- Matches 5m and 7m extension cables.
- Interfaces with industrial PLCs directly.
- Alternative Models & Differences
- 991-25-XX-01-05: Uses 25-0-25 mils range instead of metric.
- 991-06-XX-02-05: Utilizes bulkhead screws instead of DIN clips.
- 990 Vibration Transmitter: Measures dynamic radial vibration, not thrust position.
- FAQ
- Q1: What is the Bently Nevada 991 Thrust Transmitter?
- A1: It is a 2-wire loop-powered device that converts axial displacement to a 4-20 mA signal for machinery control systems.
- Q2: What type of probe is compatible with this transmitter?
- A2: It accepts input from the 3300 NSv proximity probe with matching extension cables in 5 m or 7 m system lengths.
- Q3: What diagnostic features does the 991 transmitter include?
- A3: It includes PROX OUT terminals and a coaxial connector for dynamic vibration and gap voltage signal output.
- Q4: What environmental protection does this transmitter offer?
- A4: It features potted construction for high humidity environments up to 100% condensing.
- Q5: What mounting options are available?
- A5: It offers a choice of 35 mm DIN-rail clips or bulkhead mounting screws for flexible installation.
Accessories
| 122115-01 |
990/991 Test Adapter. Package includes: 990/991 Test Adapter, 9V battery, Universal ac Adapter, Power Cord (North American), User Guide and Soft Carrying Case. The 990/991 Test Adapter inverts and isolates the PROX OUT signal from the 991 Transmitter so you can connect 991 Transmitters to ac-powered diagnostic equipment. The Adapter modifies the PROX OUT signal so that it matches our Proximitor Sensor signals by performing these functions:
The 990/991 Test Adapter provides the following benefits:
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