21505-00-44-10-02 | Bently Nevada 8 mm Proximity Probe

Introduction to the Bently Nevada 21505-00-44-10-02

When machine vibration threatens uptime, the 21505-00-44-10-02 from Bently Nevada provides the precise measurement you need. This 8 mm proximity probe is part of the 7200 Proximity Transducer Systems, engineered for continuous monitoring of rotating equipment. With a calibrated range of 80 mils (2.0 mm), it captures displacement data essential for predictive maintenance.

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 peace of mind for your operations.

Key Features and Technical Specifications

• Model: Probe Proximity Vibration
• Diameter: 8 mm
• Total Length: 1.0 metre (39 inches) with tolerance +.25 metre, -.10 metre
• 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%
• Linearity: Within 0.8 mils (0.02 mm) of a 200 mV/mil straight line
• Frequency Response: 0 to 10 kHz (0 to 600,000 cpm)
• Operating Temperature: Proximitor: -60°F to +212°F; Probe and Extension Cable: -30°F to +350°F
• Relative Humidity: Up to 95%, noncondensing
• System Weight: 1.3 lbs (0.59 kg)

The scale factor of 200 mV/mil ensures high-resolution output, translating directly to accurate vibration amplitude readings. This precision helps avoid false alarms and reduces maintenance costs by detecting issues early.

Cost-Benefit and ROI Analysis

Investing in the 21505-00-44-10-02 delivers measurable returns. Its reliable performance minimizes unplanned downtime, which is often the largest cost in industrial operations. The probe's robust design, including stainless steel lead armor, extends service life and reduces replacement frequency.

Moreover, the wide operating temperature range of the Proximitor (-60°F to +212°F) ensures stable operation in harsh environments, preventing sensor failure that could lead to costly production stoppages. By providing accurate data, this probe supports condition-based maintenance, optimizing maintenance schedules and lowering overall operational expenses.

Applications in Industrial Vibration Monitoring

The 21505-00-44-10-02 is ideal for monitoring shaft vibration in turbines, compressors, pumps, and motors. Its 8 mm diameter and standard case make it compatible with many existing installations. The probe's corrosion resistance to air, water, lube oil, and certain chemicals broadens its applicability in demanding settings.

For example, in a petrochemical plant, the probe can continuously monitor a critical pump, providing early warnings of bearing wear. This allows maintenance teams to schedule repairs during planned outages, avoiding emergency shutdowns and expensive overtime labor.

Installation and Setup Guidance

Proper installation is key to maximizing the probe's performance. The 21505-00-44-10-02 features 3/8-24 threads and includes a miniature male coaxial connector for secure signal transmission. When mounting, ensure the probe face is positioned within the calibrated range, approximately 10 mils (0.25 mm) from the target surface.

Follow the manufacturer's guidelines for gap adjustment and cable routing to avoid signal interference. Always verify the power supply meets the -17.5 Vdc to -26 Vdc requirement to ensure accurate readings.

Maintenance and Reliability Tips

Regular inspection of the probe and its connections is essential for long-term reliability. Check for any physical damage to the lead armor and ensure the connector remains tight. The probe's corrosion resistance reduces maintenance needs, but periodic verification of output signals is recommended.

Because the probe operates in environments up to 95% relative humidity, ensure that any junction boxes or conduits are properly sealed to prevent moisture ingress. These simple steps help maintain measurement accuracy and extend the probe's service life.

Compatibility and Integration

The 21505-00-44-10-02 is designed to work with Bently Nevada 7200 series monitoring systems. It provides a standard 200 mV/mil output that is compatible with most vibration monitors and data acquisition systems. For seamless integration, verify that your system accepts this scale factor and frequency response.

If you are upgrading an existing system, this probe can often replace older models without major modifications, thanks to its standard 8 mm size and thread configuration.

Troubleshooting Common Issues

If you encounter erratic readings, first check the power supply voltage. The probe requires -17.5 Vdc to -26 Vdc; deviations can cause inaccurate output. Also, inspect the probe tip for any buildup of contaminants, which can affect the gap and scale factor.

Another common issue is cable damage. The stainless steel armor protects against abrasion, but inspect it periodically. If the signal is lost, test the connector and cable continuity. For persistent problems, consult the official Bently Nevada documentation or contact Petro Auto Tech for support.

Frequently Asked Questions

Q: What is the calibrated range of the 21505-00-44-10-02?

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 operates on -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).

Q: What are the operating temperature limits?

A: The Proximitor operates from -60°F to +212°F, while the probe and extension cable handle -30°F to +350°F.

Q: Is the probe corrosion resistant?

A: Yes, for 8 mm probes, operation is not affected by direct contact with air, water, lube oil, ammonium hydroxide, sulfuric acid (10%), MEK, or DMF.

Product Support and Availability

The 21505-00-44-10-02 is available from Petro Auto Tech, an industrial automation parts supplier. As a new and original product, it comes with a 12-month factory warranty. Contact Petro Auto Tech to confirm current stock and lead times.