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Phone: +86 16626708626Description
Key Technical Specifications
| Parameter | Value |
| Compatible Probes | 7200 Series 5 mm and 8 mm Proximity Probes |
| Scale Factor / Sensitivity | 200 mV/mil (8 V/mm) ±5% |
| Linear Range | 80 mils (2.0 mm) |
| Supply Voltage | -24 VDC nominal (-17.5 to -26 VDC) |
| Frequency Response | 0 Hz (DC) to 10 kHz (-3 dB) |
| Target Material Standard | AISI 4140 steel (custom calibration available) |
| System Compatibility | Bently Nevada 3300, 7200, and 9000 Monitoring Racks |
| Operating Temperature | -45 °C to +65 °C (-50 °F to +150 °F) |
| Mounting Style | DIN-rail or flat panel plate mounting |
| Dimensions (H x W x D) | 102 mm x 114 mm x 132 mm |
| Certifications | CSA, BASEEFA/ATEX (hazardous area rated) |
Product Introduction & Supply Chain Strategy
The Bently Nevada 18745-03 is a 7200 Series Proximitor Sensor engineered for non-contact measurement of shaft radial vibration, axial thrust position, and eccentricity in critical rotating machinery. It converts eddy current resistance variations from a 5 mm or 8 mm probe into a linear voltage signal proportional to the physical gap distance.
Maintaining this unit as New Surplus is a vital risk-mitigation strategy for power generation, petrochemical, and marine propulsion plants relying on legacy 3300 or 7200 monitoring racks. Refurbished proximitors frequently suffer from drifted calibration curves, degraded potting compound, and compromised signal-to-noise ratios—defects that risk false trips or unmonitored bearing failures on high-value turbomachinery.
Installation & Configuration Guide
1.Pre-Installation & Safety Prep:10-15 min.
Bypass or disable the associated machinery protection channel on the 3300/9000 rack to prevent accidental machine trips. Wear a grounded ESD wrist strap, and verify the probe tip and coaxial extension cable lengths match the required 5-meter or 9-meter total system tuning.
2.Removal:5 min.
Disconnect the BNC/SMA coaxial extension cable from the Proximitor input jack. Unplug the -24 VDC power supply, Signal, and Common wires from the terminal block. Remove the mounting screws securing the baseplate to the enclosure.
3.Mounting & Calibration Verification:10 min.
Fasten the replacement 18745-03 module into the junction box or DIN rail. Connect the coaxial extension cable, ensuring the connection is insulated with teflon tape or boot covers to prevent accidental grounding to the junction enclosure.
4.Wiring & Gap Adjustment:10 min.
Reconnect the terminal leads: -24 VDC power, Signal output, and Common ground. Apply power and measure the DC gap voltage with a digital multimeter between Signal and Common. Adjust probe position until the bias voltage reads approximately -10.0 VDC (center of the 80-mil linear range).
- 18745-03
- 18745-03
Firmware/Software Versions & Upgrade Notes
- System Tuning Requirement: The 18745-03 is an analog signal conditioner. System accuracy depends entirely on matching the Proximitor to the correct probe diameter (5 mm or 8 mm) and total electrical cable length (5 m or 9 m).
- Target Material Calibration: Standard factory calibration is set for AISI 4140 steel. If monitoring shafts made of stainless steel, monel, or specialized alloys, scale factor adjustments must be applied at the 3300 monitor or DCS software configuration.
- Cable Length Swap Hazard: Replacing a 5-meter system proximitor with an 18745-03 configured for a 9-meter setup will distort the scale factor away from 200 mV/mil, introducing measurement error into the vibration monitoring system.
Frequently Asked Questions (FAQ)
Is this Bently Nevada 18745-03 unit authentic New Surplus?
Yes, this unit is 100% Brand New Surplus. It has never been deployed in an active plant enclosure, pulled from a decommissioned turbine, or refurbished.
Can the 18745-03 be used with 3300 XL series probes?
The 18745-03 is designed specifically for standard 7200 Series 5 mm and 8 mm probes and extension cables. While 3300 XL probes function on eddy current principles, using mismatched series components can alter the 200 mV/mil scale factor linearity.
Why should I choose New Surplus over refurbished proximitors?
Refurbished sensor units often contain aged capacitors and worn coaxial connectors that degrade under continuous field temperatures up to +65 °C. A faulty proximitor can report incorrect vibration spikes, causing an emergency trip that costs tens of thousands of dollars per hour in lost production. New Surplus delivers full original factory reliability.
How do I check if the Proximitor is operating correctly after installation?
Measure the DC voltage output across the Signal and Common terminals. At mid-gap, the voltage should read around -10 VDC. An output reading near 0 VDC indicates a shorted cable or probe touching the target, while a reading near -22 VDC indicates an open circuit or excessive gap.
Does the 18745-03 require isolated grounding?
Yes. The outer shield of the coaxial connector must remain isolated from local machine ground to prevent ground loops that introduce electrical noise into the 0–10 kHz vibration signal. Use insulated mounting plates or rubber isolation boots on coaxial connectors inside junction boxes.
What warranty coverage is included with this unit?
We cover this unit with a 1-year replacement warranty. Every 18745-03 unit passes visual inspection, terminal continuity checks, and anti-static packaging procedures before dispatch.
