Description

The Bently Nevada 128987-130-00-00, also cataloged as the 128987-130-00-00 3300 XL 8 mm Proximity, operates as a dedicated hardware component for gap displacement monitoring and dynamic shaft vibration measurement within machinery protection TSI platforms.

Suffix Breakdown & Model Matrix

• Base Model (128987): 3300 XL 8 mm proximity probe assembly with standard metric threads and coaxial ClickLoc connector interface.
• Option -130: Total cable length option indicating 3.3 meters (130 inches) of integrated coaxial cable.
• Option -00: Agency approval option designating non-hazardous area standard construction.
• Option -00: Mounting thread option designating standard fractional or metric threading configuration based on probe case design.

Hardware Specifications

Eddy-Current Probe Scaling and Gap Voltage Validation

Accurate signal transduction relies upon the interaction between the probe tip electromagnetic field and the target shaft surface. The transducer system maintains a nominal scale factor of -200 mV/mil across the linear operating range. During system installation and calibration, gap voltage validation requires a baseline output target of -10 VDC when the probe tip is spaced at the midpoint of the linear range from the conductive target. Signal conditioning circuits process this high-frequency carrier signal to eliminate cross-talk suppression issues and reject electromagnetic interference from adjacent high-voltage machinery wiring.

Frequently Asked Questions

Q: What is the nominal output sensitivity of the 3300 XL 8 mm transducer system?

A: The sensitivity is calibrated to -7.87 V/mm, which equals -200 mV/mil across the linear measurement range.

Q: How is the initial static gap voltage set during calibration?

A: The static gap voltage must be adjusted to target a nominal -10 VDC output at the monitor rack using a digital voltmeter when positioned relative to the shaft.

Q: What precautions should be taken with the coaxial cable connector?

A: The ClickLoc connector must be hand-tightened until locked and protected with insulating heat shrink or a connector protector to prevent signal degradation from moisture or oil contamination.

Field Installation Guidelines

• Mount the probe securely into the machinery bracket using proper locking nuts to prevent mechanical loosening caused by continuous high-amplitude machine vibration.
• Maintain a minimum radial clearance distance from adjacent probes and conductive structures to eliminate mutual magnetic interference and signal distortion.
• Route the coaxial extension cable away from high-power motor leads, variable frequency drive outputs, and heavy electrical conduits to prevent electromagnetic noise coupling.
• Ensure the overall shield and connector grounds remain isolated from machine ground loops to preserve common-mode noise rejection across the monitoring loop.