21505-00-72-10-02 | Bently Nevada 8 mm Proximity Probe

Introduction to the Bently Nevada 21505-00-72-10-02

When machinery vibration threatens uptime, the 21505-00-72-10-02 from Bently Nevada provides precise, real-time data. This 8 mm proximity probe is part of the 7200 Proximity Transducer Systems, engineered for continuous monitoring of shaft vibration and position. With a calibrated range of 80 mils (2.0 mm), it delivers accurate measurements that help prevent catastrophic failures.

Manufactured by Bently Nevada, a trusted name in industrial condition monitoring, this probe is supplied new and in original factory packing. It includes a 12-month factory warranty, ensuring reliability from the start.

Key Features and Technical Specifications

• Model: Probe Proximity Vibration – designed for non-contact vibration measurement.
• Total Length: 1.0 metre (39 inches) with tolerance of +0.25 metre, -0.10 metre (+10 inches, -4 inches).
• Power Requirement: -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 the 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.
• System Weight: 1.3 lbs (0.59 kg).

These specifications make the 21505-00-72-10-02 a reliable choice for demanding industrial environments.

Applications and Use Cases

The 21505-00-72-10-02 is ideal for monitoring vibration in rotating equipment such as turbines, compressors, pumps, and motors. Its 8 mm diameter and threaded 3/8-24 configuration allow easy installation in standard mounting holes. The stainless steel lead armor protects the cable in harsh conditions, while the miniature male coaxial connector ensures secure signal transmission.

Because the probe operates over a frequency range of 0 to 10 kHz, it captures both low-speed shaft runout and high-speed vibration. This makes it suitable for machinery operating at various speeds, from slow rotating kilns to high-speed spindles.

Installation and Setup

Proper installation is critical for accurate readings. Mount the probe so that the target surface is within the calibrated range, typically starting at 10 mils (0.25 mm) from the probe face. Use the 3/8-24 threaded housing to secure the probe, and ensure the cable is routed without sharp bends to avoid damage.

For best results, calibrate the probe as a system with the associated Proximitor and extension cable. This ensures the scale factor and linearity meet the specified tolerances. Always follow the manufacturer's installation manual for detailed procedures.

Maintenance and Reliability

Routine inspection of the probe and cable helps maintain reliable operation. Check for physical damage, loose connections, or contamination on the probe face. Because the probe is designed to resist corrosion from air, water, lube oil, ammonium hydroxide, sulfuric acid (10%), MEK, and DMF, it can withstand many industrial environments.

Regularly verify the output signal against a known reference to ensure accuracy. If readings drift, recalibrate the system. Following these practices extends the service life and reduces downtime.

Compatibility and Integration

The 21505-00-72-10-02 is part of the 7200 Proximity Transducer Systems, designed to work with Bently Nevada monitors and diagnostic equipment. It outputs a proportional DC voltage that can be fed into vibration monitoring systems for analysis and alarm generation.

For integration, use the specified connector option (miniature male coaxial) and ensure the power supply meets the -17.5 Vdc to -26 Vdc requirement. This probe is compatible with standard Bently Nevada extension cables and Proximitors, but always verify compatibility with your specific system.

Troubleshooting Common Issues

If the output signal is erratic or absent, check the power supply voltage and current. Ensure the probe is within the calibrated gap range. Inspect the cable for breaks or shorts, especially near the connector. If the signal is noisy, verify that the probe is not contacting the shaft and that the mounting is secure.

Temperature variations can affect the scale factor, so account for this in critical measurements. If problems persist, consult the official Bently Nevada documentation or contact Petro Auto Tech for technical support.

FAQ

Q: What is the calibrated range of the 21505-00-72-10-02?

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 is required?

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

Q: What is the frequency response?

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

Q: What is the scale factor?

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

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

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

Product Support and Availability

The 21505-00-72-10-02 is available from Petro Auto Tech, an industrial automation parts supplier. It is in stock and ready to ship. For ordering or technical inquiries, contact Petro Auto Tech for prompt assistance.