21504-12-52-05-02 | Bently Nevada 8 mm Probe Proximity Vibration

Buyer’s Guide: Evaluating the 21504-12-52-05-02 Bently Nevada Probe

When selecting a proximity transducer for critical rotating machinery, you need a sensor that offers reliable performance under demanding conditions. The 21504-12-52-05-02 from Bently Nevada is an 8 mm probe designed for continuous vibration and position monitoring. This guide helps you assess its key specifications and determine if it fits your application.

Key Technical Specifications

• Model: 21504 7200 Proximity Transducer System
• Unthreaded Length Option: 120 mm
• Overall Case Length: 5.2 inches
• Total Length: 0.5 metre (20 inches), tolerance +0.13 metre / -0.05 metre
• Connector: Miniature male coaxial connector
• Probe Diameter: 8 mm
• Threads: 3/8-24
• Power: -17.5 Vdc to -26 Vdc at 12 mA maximum consumption
• Calibrated Range: 80 mils (2.0 mm), begins at approximately 10 mils (0.25 mm) from probe face
• Scale Factor: 200 mV/mil (7.87 V/mm), ±4% (system calibrated); ±9.5% including interchangeability errors
• Linearity: Within 0.8 mils (0.02 mm) of a 200 mV/mil straight line (system calibrated); within 2.3 mils (0.06 mm) including interchangeability errors
• Frequency Response: 0 to 10 kHz (0 to 600,000 cpm); -5% at 10 kHz
• Temperature Sensitivity: Typically -3% change in scale factor at +150°F (+65°C) at 50 mils gap (1.27 mm)
• Operating Temperature (Proximitor): -60°F to +212°F (-51°C to +100°C)
• Operating Temperature (Probe and Extension Cable): -30°F to +350°F (-34°C to +177°C)
• Relative Humidity: To 95%, noncondensing
• Corrosion Resistance: Unaffected by air, water, lube oil, ammonium hydroxide, sulfuric acid (10%), MEK, or DMF
• System Weight: 1.3 lbs (0.59 kg)

Why Scale Factor Accuracy Matters

The 21504-12-52-05-02 offers a scale factor of 200 mV/mil with ±4% accuracy when calibrated as a system. This precision is critical for detecting subtle shaft vibrations that could indicate bearing wear or imbalance. Even with interchangeability errors, the tolerance stays within ±9.5%, ensuring consistent readings across multiple probes.

Installation and Setup Tips

Mount the probe using the 3/8-24 thread into a standard mounting hole. Ensure the total length of 0.5 metre (20 inches) meets your clearance requirements. The miniature coaxial connector simplifies wiring to the proximitor. For best linearity, calibrate the probe and proximitor together as a system. Follow Bently Nevada’s recommended gap settings to operate within the calibrated range of 80 mils.

Maintenance and Reliability

Routine inspection of the probe tip and cable is recommended to prevent damage from vibration or contamination. The 8 mm probe resists corrosion from common industrial fluids, reducing maintenance frequency. With a wide operating temperature range for both the probe and proximitor, the 21504-12-52-05-02 performs reliably in harsh environments.

Compatible Systems

This probe is part of the Bently Nevada 7200 Proximity Transducer System. It integrates with compatible Bently Nevada monitors and diagnostic equipment. For specific system compatibility, refer to the official documentation or contact Petro Auto Tech.

Frequently Asked Questions

Q: What is the calibrated range of the 21504-12-52-05-02?

A: The calibrated range is 80 mils (2.0 mm), beginning at approximately 10 mils (0.25 mm) from the probe face.

Q: What power supply does the 21504-12-52-05-02 require?

A: It requires -17.5 Vdc to -26 Vdc at 12 mA maximum consumption.

Q: What is the frequency response of this probe?

A: The frequency response is 0 to 10 kHz (0 to 600,000 cpm), with -5% at 10 kHz.

Q: Can the probe withstand corrosive environments?

A: Yes, the 8 mm probe is unaffected by air, water, lube oil, ammonium hydroxide, 10% sulfuric acid, MEK, or DMF.

Q: What is the system weight of the 21504-12-52-05-02?

A: The system weight is 1.3 lbs (0.59 kg).

Product Support and Availability

The 21504-12-52-05-02 is available as new and original in factory packing with a 12-month warranty. Contact Petro Auto Tech for current stock and ordering details.