21504-00-40-05-02 | Bently Nevada 8 mm Proximity Probe Vibration Transducer

Introduction to the Bently Nevada 21504-00-40-05-02

In the evolving landscape of industrial automation, the need for precise vibration monitoring has never been greater. The 21504-00-40-05-02 from Bently Nevada addresses this demand with a robust 8 mm proximity probe designed for continuous shaft vibration and position measurement. As part of the trusted 7200 Proximity Transducer Systems, this model offers a calibrated range of 80 mils (2.0 mm) and a scale factor of 200 mV/mil (7.87 V/mm), ensuring accurate data for predictive maintenance. Engineers rely on this transducer to detect early signs of mechanical wear, reducing unplanned downtime and extending equipment life.

Key Features and Technical Specifications

• The 21504-00-40-05-02 operates on an input power of -17.5 Vdc to -26 Vdc with a maximum consumption of 12 mA.
• Its calibrated range begins at approximately 10 mils (0.25 mm) from the probe face, covering up to 80 mils (2.0 mm).
• Scale factor is 200 mV/mil (7.87 V/mm) with a system accuracy of ±4% and ±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.
• Frequency response spans 0 to 10 kHz (0 to 600,000 cpm) with -5% at 10 kHz (600,000 cpm).
• Temperature sensitivity is typically -396 change in scale factor at +150°F (+65°C) at a 50 mils gap (1.27 mm).
• Environmental limits include an operating temperature range for the Proximitor of -60°F to +212°F (-51°C to +100°C) and for the probe and extension cable of -30°F to +350°F (-34°C to +177°C).
• Relative humidity tolerance is up to 95%, noncondensing.
• The system weight is 1.3 lbs (0.59 kg).

Real-World Applications and Use Cases

This proximity probe is commonly deployed in rotating machinery such as turbines, compressors, and pumps. For example, in a steam turbine application, the 21504-00-40-05-02 continuously monitors shaft vibration, providing early warning of imbalance or misalignment. Its corrosion resistance to air, water, lube oil, ammonium hydroxide, sulfuric acid (10%), MEK, and DMF makes it suitable for harsh industrial environments. Consequently, maintenance teams can schedule repairs proactively, avoiding catastrophic failures and reducing overall operational costs.

Installation and Setup Guidance

When installing the 21504-00-40-05-02, ensure the probe face is positioned approximately 10 mils (0.25 mm) from the target surface to begin the calibrated range. The unthreaded length option is 0 mm, overall case length is 4 inches, and total length is 0.5 metre (20 inches) with a tolerance of +0.13 metre, -0.05 metre (+5 inches, -2 inches). The connector option includes a miniature male coaxial connector. Mount the probe securely using the standard 318-24 threads, and avoid bending the lead armor beyond its rated limits. For best results, follow the manufacturer's wiring diagram and verify power supply within -17.5 Vdc to -26 Vdc.

Maintenance and Reliability Tips

To maintain reliable performance, inspect the probe and cable periodically for physical damage or contamination. The 21504-00-40-05-02 is designed to operate in environments with up to 95% relative humidity, but regular cleaning of the probe face with a soft cloth helps preserve accuracy. Since the system is not safety-rated (no SIL, ATEX, or IECEx certifications mentioned), follow standard industrial safety practices during maintenance. By incorporating this transducer into a routine vibration monitoring program, facilities can extend machinery service life and minimize unexpected downtime.

Compatibility and Integration

The 21504-00-40-05-02 integrates seamlessly with Bently Nevada 7200 series monitoring systems. It outputs a 200 mV/mil signal compatible with most vibration data collectors and online monitoring platforms. No specific communication protocols (such as EtherNet/IP or Modbus) are listed in the provided data, so consult the official documentation for interface details. For replacement or upgrade projects, this model directly substitutes earlier 8 mm proximity probes within the same series.

Frequently Asked Questions

Q: What is the calibrated range of the 21504-00-40-05-02?

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 21504-00-40-05-02 require?

A: It requires an input power of -17.5 Vdc to -26 Vdc with a maximum consumption of 12 mA.

Q: What is the frequency response of this proximity probe?

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

Q: What is the total length and connector type for the 21504-00-40-05-02?

A: The total length is 0.5 metre (20 inches) with a miniature male coaxial connector.

Q: What environmental conditions can the 21504-00-40-05-02 withstand?

A: The Proximitor operates from -60°F to +212°F (-51°C to +100°C), and the probe and cable from -30°F to +350°F (-34°C to +177°C), with up to 95% noncondensing humidity.

Product Support and Availability

The Bently Nevada 21504-00-40-05-02 is available as new and original in factory packing from Petro Auto Tech. Each unit carries a 12-month factory warranty. Please verify current lifecycle status and availability with Petro Auto Tech before ordering, as this information is not specified in the provided data.