Product Overview

The Bently Nevada 330102-04-25-10-02-00 is an armored 3300 XL 8 mm proximity probe used for non-contact shaft displacement measurement in rotating machinery. It detects changes in the distance between the probe tip and a conductive target, allowing a compatible Proximitor Sensor to generate a signal representing relative shaft movement.

In centrifugal compressors, steam turbines, and pumps equipped with fluid-film bearings, shaft displacement measurements are commonly used to monitor rotor vibration and position. A probe installed near a bearing can detect changes in shaft movement as operating speed, load, or mechanical conditions change. The monitoring system can then trend these measurements and alert maintenance personnel when readings move outside configured operating limits.

This particular configuration uses a 3/8-24 UNF mounting thread, a 0.4-inch unthreaded section, a 2.5-inch overall case length, and a 1-meter total length. Its armored cable provides additional mechanical protection compared with an unarmored version. The ordering code also specifies a miniature coaxial ClickLoc connector without a connector protector and the 00 approval option.

The probe belongs to the 3300 XL 8 mm Proximity Transducer System. It must be matched with a compatible extension cable and Proximitor Sensor to form the intended electrical measurement loop. When replacing a probe on existing machinery, engineers should verify the full part number and the installed transducer configuration rather than selecting a replacement based only on the 8 mm probe diameter.

Technical Specifications

Product Features

• Non-contact shaft measurement: Detects relative movement between a probe and conductive target without physical contact with the rotating surface.
• 8 mm sensing tip: Supports the specified measurement range of the 3300 XL 8 mm transducer system.
• Armored cable construction: Adds mechanical protection in installations where the cable may be exposed to abrasion or other physical hazards.
• Defined mounting interface: The 3/8-24 UNF thread supports installations configured for this particular mounting arrangement.
• 1-meter total length: Suits applications requiring the corresponding probe-length option.
• ClickLoc connector: Provides the specified miniature coaxial connection for compatible system components.
• Dynamic measurement capability: Supports shaft-motion measurements across the system’s specified frequency response.
• Matched-system characteristics: The nominal scale factor and linear range apply to the compatible probe, extension cable, and Proximitor Sensor arrangement.
• Maintenance identification: The complete ordering code distinguishes the probe’s mechanical, cable, connector, and approval configuration.

Working Principle

The 330102-04-25-10-02-00 operates through eddy-current sensing. A compatible Proximitor Sensor generates a high-frequency electrical signal that travels through the extension cable to the probe coil. When the probe faces a conductive target, the electromagnetic field induces eddy currents in the target material. Changes in the gap between the probe tip and the target alter the electrical response of the circuit.

The measurement path is:

Rotating Shaft → 3300 XL 8 mm Probe → Extension Cable → Proximitor Sensor → Machinery Monitoring System

As the shaft moves relative to the probe, the distance between the two surfaces changes. The Proximitor Sensor converts this change into an electrical output that the monitoring system can interpret as shaft displacement. Depending on probe orientation and channel configuration, the measurement may be used to monitor radial vibration, axial position, or another supported shaft-motion parameter.

For example, a centrifugal compressor may use two probes positioned at different angular locations near a bearing. Each probe measures shaft movement along its sensing direction. The monitoring system evaluates these signals to track vibration behavior and identify changes that may require inspection. Engineers can compare the readings with operating speed, load, and historical trends before determining whether the change reflects a mechanical issue.

The nominal scale factor of 7.87 V/mm and linear measurement range of 2 mm apply to the specified 3300 XL 8 mm transducer system. For radial vibration applications, the nominal installation gap is approximately 1.27 mm, corresponding to a nominal gap voltage of −9 V DC. The actual setup must follow the applicable installation procedure and system requirements.

The probe’s total electrical length must match the intended extension cable and Proximitor Sensor arrangement. An incorrect combination can affect measurement performance even when the probe itself is functioning normally. Target material, mounting alignment, gap setting, and connector condition should also be checked during installation and troubleshooting.

Role in a Machinery Monitoring Architecture

The 330102-04-25-10-02-00 serves as the sensing element in a 3300 XL 8 mm proximity measurement channel. It detects shaft displacement and passes the signal through a compatible extension cable to the Proximitor Sensor. The sensor output is then acquired by the monitoring equipment for measurement, trending, and protection functions.

Shaft Surface → Proximity Probe → Extension Cable → Proximitor Sensor → Vibration Monitor → Alarm and Protection Logic

The probe supplies measurement data but does not independently diagnose a fault or initiate a shutdown. Diagnostic interpretation and protective action depend on the monitoring equipment, channel configuration, and plant protection logic.

Industrial Applications

The probe is suitable for applications where non-contact shaft measurement is required and the 3300 XL 8 mm system’s measurement range, target characteristics, and mounting arrangement are appropriate. The measurement direction and monitoring function should be established before installation.

Installation and Maintenance

1. Verify the complete part number: Confirm 330102-04-25-10-02-00, including its thread, case length, total length, connector, and approval option.
2. Check the mounting thread: Verify that the mounting point accepts the specified 3/8-24 UNF-2A thread and that the mounting hardware is undamaged.
3. Inspect the probe tip: Look for impact damage, contamination, or surface defects that could affect the sensing response.
4. Confirm the insertion depth: Check that the unthreaded section and case length suit the mounting arrangement and allow correct probe positioning.
5. Inspect the armored cable: Examine the armor and cable jacket for crushing, abrasion, sharp bends, or other physical damage.
6. Protect the cable route: Keep the cable away from moving components, sharp edges, and surfaces that exceed its permitted operating conditions.
7. Check the ClickLoc connector: Inspect the connector for contamination or damage and confirm proper engagement with the matching connection.
8. Verify the transducer loop: Confirm that the extension cable and Proximitor Sensor are compatible with the 1-meter probe configuration.
9. Set the probe gap: Establish the required gap using the approved installation procedure and the appropriate target material.
10. Check the electrical output: Verify the gap voltage and signal response against the applicable system specifications.
11. Validate the monitoring channel: Confirm channel scaling, measurement direction, alarm settings, and baseline readings after installation.
12. Record the commissioning results: Document the probe model, associated cable and sensor models, gap setting, wiring checks, and functional test results.

If the monitoring channel produces unexpected readings after replacement, check the probe gap, target surface, connector engagement, cable continuity, and Proximitor Sensor compatibility before assuming that the shaft itself has developed a fault. Follow the site’s approved isolation and machinery safety procedures when working around rotating equipment.

Compatible System Components

The 330102-04-25-10-02-00 operates as part of a matched 3300 XL 8 mm proximity transducer system. The probe, extension cable, and Proximitor Sensor must be compatible with the intended electrical configuration and measurement application.

Recommended Related Models

Key Advantages

• Measures shaft vibration and position without physical contact.
• Uses an armored cable configuration for additional mechanical protection.
• Supports a nominal 2 mm linear measurement range.
• Offers a 1-meter total-length option for compatible system configurations.
• Supports dynamic measurements across the specified frequency range.
• Integrates with compatible 3300 XL 8 mm extension cables and Proximitor Sensors.

Technical FAQs

What does the ordering code 330102-04-25-10-02-00 identify?

The ordering code identifies an armored 3300 XL 8 mm probe with a 3/8-24 UNF mounting thread, a 0.4-inch unthreaded section, a 2.5-inch overall case length, a 1-meter total length, and a miniature coaxial ClickLoc connector without a connector protector. The final suffix identifies the specified approval option.

Can this probe be connected directly to a Bently Nevada 3500 monitor?

No. The probe normally connects through a compatible 3300 XL 8 mm extension cable to a matching Proximitor Sensor. The sensor output is then connected to the appropriate monitoring input.

Why must the total electrical length match the existing transducer system?

The probe, extension cable, and Proximitor Sensor form a matched electrical measurement loop. An incompatible combination can affect the electrical characteristics and measurement accuracy. Verify all three components before replacing the probe.

What should be checked if vibration readings change after probe replacement?

Check the complete part number, mounting position, target material, probe gap, extension cable, Proximitor Sensor, and monitoring-channel configuration. Once the transducer loop has been verified, compare the readings with machine speed, load, and historical baseline data to determine whether the difference reflects actual shaft movement.