Technical Specifications

FAQ

1. What is the main function of the Bently Nevada 21504-04-36-10-02 probe?

This probe is designed for continuous non-contact monitoring of rotating machinery shafts. Its primary function is to measure shaft vibration, radial displacement, and axial position in real time. By detecting extremely small changes in the gap between the probe tip and the conductive shaft surface, it generates a proportional electrical signal that reflects mechanical behavior. This data is widely used for condition monitoring, predictive maintenance, and protection systems in critical rotating equipment such as turbines, compressors, pumps, and motors.

2. How does the eddy current measurement principle work?

The probe operates based on the eddy current principle. A high-frequency electromagnetic field is generated at the probe tip. When a conductive metal target such as a steel shaft enters this field, eddy currents are induced on the surface of the material. These currents change the impedance of the probe coil, and the system converts this change into a stable voltage signal proportional to the distance between the probe and the target. This allows highly accurate, non-contact measurement even in harsh industrial environments.

3. What types of machinery is this probe typically used on?

This probe is commonly used on critical rotating machinery where continuous monitoring is required for safe operation. Typical applications include steam turbines, gas turbines, centrifugal compressors, industrial pumps, electric motors, and gearboxes. In these machines, small changes in shaft motion can indicate early-stage faults such as imbalance, misalignment, bearing wear, or rotor instability, making continuous monitoring essential for reliability.

4. What type of output signal does the probe provide?

The probe provides a continuous analog voltage signal that varies in proportion to the distance between the probe tip and the shaft surface. This raw signal is processed by a compatible Bently Nevada monitoring system, which converts it into engineering values such as vibration amplitude, shaft displacement, or axial position. These values are then used for trending, alarm thresholds, and machine protection logic.

5. Is the probe suitable for harsh industrial environments?

Yes, the probe is designed specifically for harsh industrial conditions. It can operate reliably in environments with high vibration, temperature variation, and strong electromagnetic interference. Its rugged construction and shielding ensure stable signal transmission even when installed near heavy rotating machinery or electrical equipment, supporting long-term continuous operation.

6. Does the probe require calibration after installation?

Yes, calibration is required after installation. The calibration process establishes the correct relationship between output voltage and the actual physical gap between the probe and the shaft. This ensures that vibration and displacement readings accurately represent real machine conditions and maintain measurement accuracy for protection and diagnostic functions.

7. Which systems is this probe compatible with?

This probe is designed to work with the Bently Nevada 7200 series monitoring system. It integrates with compatible proximitor modules and monitoring racks to form a complete measurement chain. When properly installed, it provides reliable real-time signals for vibration monitoring, shaft displacement tracking, and machine protection applications.

8. What maintenance practices are recommended for this probe?

Recommended maintenance includes periodic inspection of mounting stability, cable condition, and signal quality. The probe should remain firmly secured to avoid misalignment caused by vibration. Cable shielding should be checked to prevent noise or signal degradation. The probe tip area should also be kept clean and free from oil, dust, or debris, as contamination can affect measurement accuracy over time. Regular system checks help ensure stable long-term performance.