21504-00-12-05-02 | Bently Nevada 8 mm Proximity Probe Vibration Transducer

What Makes the 21504-00-12-05-02 Essential for Vibration Monitoring?

When unexpected machine downtime threatens production schedules, the 21504-00-12-05-02 from Bently Nevada provides reliable proximity vibration sensing. This 8 mm probe is part of the Model 21504 7200 Proximity Transducer Systems family, designed for continuous monitoring of rotating equipment. It offers a calibrated range of 80 mils (2.0 mm) and begins sensing at approximately 10 mils (0.25 mm) from the probe face. With a scale factor of 200 mV/mil (7.87 V/mm), it delivers accurate readings for predictive maintenance strategies.

Key Features and Technical Specifications of the 21504-00-12-05-02

• Probe Diameter: 8 mm with standard case configuration.
• Threads: 3/8-24 for secure mounting.
• Unthreaded Length: 0 mm; overall case length is 120 mm.
• Total Length: 0.5 metre (20 inches) with tolerance of +0.13 metre, -0.05 metre.
• Connector: Miniature male coaxial connector option.
• Power Input: -17.5 Vdc to -26 Vdc at 12 mA maximum consumption.
• Calibrated Range: 80 mils (2.0 mm), beginning at approximately 10 mils (0.25 mm) from probe face.
• Scale Factor: 200 mV/mil (7.87 V/mm), ±4% when calibrated as a system; within ±9.5% including interchangeability errors.
• Linearity: Within 0.8 mils (0.02 mm) of a 200 mV/mil straight line when calibrated as a system; 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 (600,000 cpm).
• 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); Probe and Extension Cable: -30°F to +350°F (-34°C to +177°C).
• Relative Humidity: Up to 95%, noncondensing.
• Corrosion Resistance: For 8 mm probes only; unaffected by air, water, lube oil, ammonium hydroxide, sulfuric acid (10%), MEK, or DMF.
• System Weight: 1.3 lbs (0.59 kg).

Real-World Applications for the Bently Nevada 21504-00-12-05-02

In industrial environments, the 21504-00-12-05-02 excels at monitoring shaft vibration and position in turbines, compressors, and pumps. Its 8 mm probe size fits standard mounting configurations, making it suitable for retrofitting existing machinery. The wide frequency response from 0 to 10 kHz captures both low-speed and high-speed rotational dynamics. Additionally, its corrosion-resistant design allows reliable operation in harsh conditions involving lubricants or mild chemicals.

Installation and Setup Guidance

Proper installation of the 21504-00-12-05-02 begins with verifying the mounting thread (3/8-24) and ensuring the probe face is clean. The unthreaded length of 0 mm means the entire case length of 120 mm is threaded, so careful positioning is needed to avoid interference. Connect the miniature male coaxial connector securely to the extension cable. Always follow the manufacturer's manual for gap setting and initial calibration to achieve the specified scale factor accuracy.

Maintenance and Reliability Tips

To maintain consistent performance, inspect the probe and cable periodically for physical damage or contamination. The 21504-00-12-05-02 operates reliably within its temperature limits, but verify that ambient conditions stay within -30°F to +350°F for the probe and cable. Regular verification of the system calibration helps preserve the ±4% scale factor accuracy. Because the probe is corrosion-resistant to many industrial fluids, routine cleaning with a soft cloth is usually sufficient.

Compatibility and Integration

The 21504-00-12-05-02 integrates seamlessly with Bently Nevada monitoring systems that accept 200 mV/mil input from proximity probes. It works with standard extension cables and proximitors that support -17.5 Vdc to -26 Vdc power. For system-level calibration, pair it with a compatible Bently Nevada monitor to achieve the specified linearity and frequency response.

Frequently Asked Questions about the 21504-00-12-05-02

Q: What is the calibrated range of the 21504-00-12-05-02?

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 21504-00-12-05-02 require?

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

Q: What is the scale factor of this proximity probe?

A: The scale factor is 200 mV/mil (7.87 V/mm), with ±4% accuracy when calibrated as a system.

Q: What is the frequency response of the 21504-00-12-05-02?

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

Q: What is the operating temperature range for the probe?

A: The probe and extension cable operate from -30°F to +350°F (-34°C to +177°C).

Product Support and Availability

The 21504-00-12-05-02 is available as a new, original factory-packed unit from Petro Auto Tech. It comes with a 12-month factory warranty. For current lifecycle status and ordering details, please contact Petro Auto Tech directly.