Product Overview

The 21504-00-08-05-02 is a precision-engineered 8 mm eddy current proximity probe belonging to the legacy 7200 series transducer line by Bently Nevada. This non-contacting sensor is designed to measure the minute gaps between the probe tip and a rotating shaft, converting mechanical displacement into a highly accurate electrical voltage. As a core element of Turbine Supervisory Instrumentation (TSI), this probe configuration features an 80 mm case length and a 0.5-meter integral cable. Its design emphasizes field durability and high-temperature resistance, ensuring it can withstand the volatile thermal and chemical environments found inside industrial machine housings.

Critical Technical Specifications

• Model Number: 21504-00-08-05-02

• Sensor Tip Diameter: 8 mm

• Mounting Configuration: Standard threaded case

• Overall Case Length: 80 mm

• Integral Cable Length: 0.5 Meter (approx. 20 inches)

• Connector Type: Miniature male coaxial ClickLoc

• Storage Temperature Range: -51°C to +177°C (-60°F to +350°F)

• Total Weight: 0.06 kg

• Shipping Dimensions: 1.8 x 1.6 x 123 cm

• Manufacturing Standards: API 670 compliant

• Country of Origin: USA

Industrial Implementation and Monitoring Uses

The 21504-00-08-05-02 is primarily deployed for the continuous protection of critical rotating assets such as steam turbines, centrifugal compressors, and large-scale industrial pumps. It is utilized to detect radial vibration, which identifies rotor imbalances, and axial thrust position to prevent catastrophic bearing failure. In addition to vibration analysis, this probe serves as an essential Keyphasor reference for phase measurements and rotational speed tracking. Because of its 0.5-meter cable length, it is ideally suited for installations where the Proximitor sensor is mounted in a local junction box located immediately adjacent to the machine casing, minimizing signal interference and cable clutter.

FAQ

Q: Is the 21504-00-08-05-02 compatible with the newer 3300 XL Proximitor sensors?

A: No, the 21504 series is part of the legacy 7200 system. While Bently Nevada offers various upgrade paths, the 7200 series probes must be used with matching 7200 Proximitors to maintain the correct scale factor and API 670 compliance.

Q: Why is the cable only 0.5 meters long on this specific model?

A: The 0.5-meter (20-inch) cable is designed for applications where the probe is connected to an extension cable immediately outside the machine casing. This helps prevent excess cable from becoming damaged inside tight conduits or machine enclosures.

Q: What is the benefit of the miniature coaxial ClickLoc connector?

A: The ClickLoc connector provides a secure, vibration-resistant connection that ensures consistent electrical continuity. The gold-plated surfaces prevent oxidation, which is vital for maintaining high-resolution data in oily or humid industrial environments.

Q: Can this probe be adjusted while the machine is running?

A: Standard mount probes are generally gapped during machine downtime. However, if installed with a specialized housing like a probe sleeve, the depth can be adjusted externally to ensure the sensor is perfectly positioned within its linear range without stopping the rotor.

Q: What target material is required for accurate measurement?

A: For the standard factory calibration to remain valid, the probe should be used with a ferromagnetic target, specifically AISI 4140 steel. If your shaft is made of a different alloy, the system will require a specific calibration to provide accurate displacement readings.