21505-00-12-05-02 | Bently Nevada 8 mm Proximity Probe 0.5 m

Introduction to the Bently Nevada 21505-00-12-05-02 Proximity Probe

When rotating machinery vibration threatens uptime, the 21505-00-12-05-02 from Bently Nevada provides precise, real-time measurement. This 8 mm proximity probe is part of the 7200 series, engineered for continuous monitoring in demanding industrial environments. Its compact design and robust construction make it a dependable choice for condition monitoring systems.

Key Features and Technical Specifications

The 21505-00-12-05-02 offers a calibrated range of 80 mils (2.0 mm), starting at approximately 10 mils (0.25 mm) from the probe face. This allows accurate measurement of shaft vibration and position. The scale factor is 200 mV/mil (7.87 V/mm) with ±4% accuracy when calibrated as a system, and within ±9.5% including interchangeability errors. Linearity is within 0.8 mils (0.02 mm) of a 200 mV/mil straight line when calibrated as a system, and within 2.3 mils (0.06 mm) including interchangeability errors.

• 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)
• Linearity: Within 0.8 mils (0.02 mm) of a 200 mV/mil straight line (system calibrated)
• Frequency Response: 0 to 10 kHz (0 to 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)
• Operating Temperature (Probe and Extension Cable): -30°F to +350°F (-34°C to +177°C)
• Relative Humidity: To 95%, noncondensing
• System Weight: 1.3 lbs. (0.59 kg)

The probe features an unthreaded length of 0 mm and an overall case length of 120 mm. The total length option is 0.5 metre (20 inches) with a tolerance of +0.13 metre, -0.05 metre (+5 inches, -2 inches). It comes with a miniature male coaxial connector and stainless steel lead armor.

Applications and Use Cases

This proximity probe is ideal for monitoring shaft vibration in turbines, compressors, pumps, and motors. Its 8 mm diameter and standard 3/8-24 thread make it easy to install in existing sensor ports. The 80 mil range covers typical vibration amplitudes in most rotating machinery, providing early warning of mechanical issues. Additionally, the probe's corrosion resistance to air, water, lube oil, ammonium hydroxide, sulfuric acid (10%), MEK, and DMF ensures reliable operation in harsh environments.

Installation and Setup

Proper installation is critical for accurate readings. Mount the probe with the specified gap (approximately 10 mils from the target) to ensure the measurement starts within the calibrated range. Use the provided connector and lead armor to protect the cable from damage. For best results, follow the manufacturer's installation guidelines and verify the system calibration after mounting.

Maintenance and Reliability

Regular inspection of the probe and cable is recommended to ensure long-term reliability. Check for any physical damage or wear, especially in high-vibration areas. The stainless steel armor provides excellent protection, but periodic verification of the system's scale factor and linearity is advised. With proper care, this probe delivers consistent performance over many years.

Compatibility and Integration

The 21505-00-12-05-02 is designed for use with Bently Nevada 7200 series monitoring systems. It can be integrated into existing condition monitoring networks, providing seamless data acquisition. For detailed compatibility information, refer to the official Bently Nevada documentation or contact Petro Auto Tech.

Frequently Asked Questions

Q: What is the calibrated range of the 21505-00-12-05-02?

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 proximity probe 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: What is the total length of the probe cable?

A: The total length option is 0.5 metre (20 inches) with a tolerance of +0.13 metre, -0.05 metre.

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 21505-00-12-05-02 is available from Petro Auto Tech, a trusted industrial automation parts supplier. It comes new and original in factory packing with a 12-month warranty. Contact Petro Auto Tech for current availability and ordering information.