Product Overview

The Bently Nevada 21504-04-36-05-02 is a specialized 5 mm proximity probe engineered for high-precision radial vibration and axial position sensing in confined industrial environments. This transducer is a fundamental component for Turbine Supervisory Instrumentation (TSI), providing critical real-time data to Bently Nevada 3500 racks or DCS platforms like Honeywell Experion. By utilizing eddy current technology, it monitors shaft motion with sub-micron resolution, ensuring early detection of mechanical anomalies in high-speed compressors, pumps, and small turbines. Its compact 5 mm tip diameter allows for installation in tight bearing housings where standard 8 mm probes cannot fit, delivering the same industrial-grade reliability and thermal stability required for mission-critical machinery protection and emergency shutdown systems.

Suffix Logic & Configuration Coding

The 21504 series utilizes a specific alphanumeric structure to define mechanical mounting and electrical cable parameters. The configuration for this unit is decoded below:

04 - Unthreaded Length Option

Specifies a 0.4-inch unthreaded length. This allows the probe to pass through a mounting bracket or housing before the threads engage, facilitating easier depth adjustment in specific casing designs.

36 - Overall Case Length Option

Indicates a 3.6-inch total case length. This mid-sized barrel provides sufficient reach for standard bearing housings while maintaining structural rigidity against mechanical harmonics.

05 - Total Length Option

Represents a 0.5-meter (1.6 feet) integral cable length. This short lead is designed for direct connection to an extension cable, minimizing the footprint within the machine's junction box.

02 - Connector and Agency Approval Option

Equipped with a miniature coaxial connector and optimized for standard industrial environments with basic agency certifications. This ensures low-impedance signal transmission and plug-and-play compatibility with 3300 series Proximitor sensors.

Essential Hardware Parameters

Field Commissioning Insights

Proper gapping is vital for signal linearity. During installation, use a high-impedance digital voltmeter to set the "Gap Voltage" to approximately -10.0 Vdc, which typically represents the center of the 80-mil linear range for 3300-series systems. Technicians must ensure the integral cable maintains a minimum bend radius of 25.4 mm (1.0 inch) to prevent internal conductor breakage. Always clean the coaxial connectors with an approved electronic contact cleaner before mating, and use a connector protector to prevent oil ingress, which can cause significant signal drift or "Not OK" status on the monitor.

Performance & System Integration

The 21504-04-36-05-02 excels in environments characterized by high-frequency vibration and thermal cycling. Its polyphenylene sulfide (PPS) tip resists chemical erosion from synthetic lubricants, ensuring long-term measurement stability. This probe integrates seamlessly with the Bently Nevada 3500/42M Proximitor Monitor, providing high-fidelity data that can be exported to System 1 software for advanced predictive maintenance. The small 5 mm form factor reduces the "target area" requirement on the shaft, making it ideal for monitoring small-diameter rotors where surface area for probe observation is limited.

Shipment & Fulfillment Details

We prioritize rapid response for all critical spare parts orders to minimize facility downtime.

Dispatch Schedule: 2-7 days when payment finish through our global express network.

Preferred Carriers: Priority shipping via DHL, FEDEX, or UPS.

Package Standards: Each probe is enclosed in anti-static industrial packaging. We utilize vacuum-sealed moisture barriers and shock-absorbing foam to guarantee the 5 mm tip and precision threads arrive in flawless, factory-sealed condition.

Precision Sensing FAQs

Q1: Can I substitute this 5 mm probe for a standard 8 mm probe?

A1: No. While they may share a 200 mV/mil scale factor, the Proximitor sensor is calibrated to a specific probe tip diameter. Using a 5 mm probe with an 8 mm Proximitor will result in significant linearity errors and false vibration data.

Q2: What is the benefit of the 0.5-meter cable (Option 05)?

A2: The 0.5m length is ideal for machines where the proximity probe junction box is mounted very close to the probe entry point, reducing excess cable "slop" and minimizing EMI/RFI pickup.

Q3: How do I verify if the probe is gapped correctly without a monitor?

A3: Connect a Proximitor and a -24Vdc power supply. Measure the voltage between the "Sig" and "Com" terminals. At the center of the linear range, you should read -10.0 Vdc relative to the target material (usually 4140 steel).

Q4: Is this probe compatible with 3300 XL extension cables?

A4: Yes, Bently Nevada 3300 probes are generally compatible with 3300 XL extension cables and Proximitors, provided the total system length (e.g., 5m or 9m) is maintained.