The Bently Nevada 21474-075-00, also cataloged as the 21474 Proximity Probe, operates as a dedicated hardware component for non-contacting shaft displacement and vibration measurement within 2000 series mechanical monitoring systems.

Model Configuration Overview

The 21474-075-00 designation identifies a specific configuration within the 2000 series transducer family. This model features a predefined probe geometry and cable termination designed for integration with legacy Bently Nevada signal conditioning monitors. The suffix values define the physical probe length and connector interface type, maintaining compatibility with established transducer mounting standards.

Hardware Specifications

Mechanical Monitoring & Eddy-Current Transduction

System accuracy depends on the stability of the eddy-current probe scaling across the linear operating range. Proper installation requires gap voltage validation; installers must adjust the probe to achieve a nominal -10 VDC gap voltage target to ensure signal linearity. Rotor dynamics analysis depends on precise output; therefore, the probe must be mounted to prevent structural resonance. Cross-talk suppression must be observed during multi-probe installations, ensuring sufficient distance between transducer tips to prevent electromagnetic interference.

## Ordering info

• 1x 21474-075-00 Proximity Probe

• 1x Probe connector protective cover

• 1x Installation technical manual

Field Installation Guidelines

• Alignment: Ensure the probe is mounted perpendicular to the target surface. Misalignment will degrade the transducer linearity.

• Threading: Engage the probe into the mounting bracket or housing, ensuring at least 5 full thread engagements for structural integrity.

• Locking: Secure the probe using the lock nut, applying a torque of 5.1 N-m (45 in-lb) to prevent movement caused by machine vibration.

• Grounding: Maintain the integrity of the coaxial cable shield from the probe connector back to the monitor input to minimize signal noise.

Frequently Asked Questions

• Is this probe compatible with 3300 XL Proximitors? No, 2000 series probes are designed for specific legacy monitors; impedance mismatches may occur with newer system components.

• How is the linear range defined? The range is defined by the distance over which the probe output remains proportional to the target displacement, typically 80 mils.

• Can I cut the probe cable? No, the probe and cable are an integrated, factory-calibrated assembly; cutting the cable invalidates the sensitivity and performance.

• What is the recommended target material? Calibration is based on 4140 steel; other conductive materials will require re-scaling factors.

• Can the probe measure shaft speed? Yes, when configured with a target keyway or notch, the voltage pulses generated can be processed for rotational speed measurement.

• What happens if the probe tip is damaged? Any physical deformation of the PPS tip will result in a loss of calibration and potentially non-linear output.

• Does this probe require hazardous area certification? Verify local documentation if installing in explosive atmospheres, as specific barriers may be required.

• What is the maximum operating temperature? The transducer is rated for operation up to 177 deg C, assuming proper selection of cable materials.