The Bently Nevada 21504-000-024-10-02, also cataloged as the 21504 Proximity Probes, operates as a dedicated hardware component for non-contacting vibration and displacement measurement within 3500 Machinery Protection Systems. The component tracks continuous physical displacement by establishing a radio-frequency eddy-current field between the 8 mm probe tip and a rotating target, transforming gap variation parameter metrics into precise electrical monitoring signals.

Options and Matrix Architecture

• 21504: 8 mm Standard Mount Proximity Probe assembly, 3/8-24 UNF thread pattern

• -000: Unthreaded length option (0.0 inches)

• -024: Overall case length option (2.4 inches)

• -10: Total length option (1.0 meter / 3.3 feet)

• -02: Miniature coaxial ClickLoc connector with pre-installed connector protector

Technical Specifications

Eddy-Current Probe Scaling and Rotor Dynamics Stability

The geometry of the internal coil determines the eddy-current probe scaling characteristics across the active 80 mil tracking curve. During physical alignment, the loop parameters require a static gap voltage validation at a target reading of -10 VDC to configure the operational envelope to the midpoint of the linear slope. For machinery monitoring involving highly reactive rotor dynamics, structural multi-probe configurations must address cross-talk suppression specifications. Parallel transducer ports require maintaining a center-to-center mechanical distance of at least 40 mm to prevent adjacent radio-frequency sensor fields from inducing cross-channel interference loops.

Package Manifest

• 1 x Bently Nevada 21504-000-024-10-02 8 mm Proximity Probe

• 1 x Pre-installed ClickLoc Coaxial Connector Protector Terminal

• 2 x 3/8-24 UNF Hex Jam Fastening Nuts

• 1 x Material Calibration Curve Certificate Log

Field Assembly Implementation Guidelines

Mechanical integration requires checking thread engagement parameters and clearance paths prior to setting final orientation values.

1. Clear the 3/8-24 UNF housing thread structures of residue. Hand-thread the probe casing into the target mounting block to guarantee linear alignment across the 2.4-inch body.

2. Interconnect the 1.0-meter integral coaxial tail line to an external matching extension cable, seating the ClickLoc connection inside its protective sleeve.

3. Advance the sensor tip down toward the target shaft using low-profile hand tools while tracking the Proximitor monitor output loop with a digital voltmeter.

4. Stop insertion immediately when the voltmeter registers gap voltage validation at -10.0 VDC. Torque the locknuts to 4.5 N-m (40 in-lb) to prevent shift during operational vibration.

5. Guide the extension line inside dedicated protective conduits, verifying that the continuous cable shield layer remains isolated from local machine structure grounds.

Handling and Dispatch Rules

Delivery time: 2-7 days when payment finish, routed internationally through DHL, FEDEX, or UPS express facilities. Items are packed inside specialized anti-static industrial packaging using shock-damping contoured foam inserts to prevent structural or alignment calibration changes during handling.

Transducer System FAQ

Q: Can the 1.0-meter probe cable interface directly into the 3500/42M monitor card input?

A: No. The probe is a passive component that requires a matched system loop length of either 5.0 meters or 9.0 meters. It must connect to a dedicated Proximitor Sensor through an intermediate extension cable to match the designed input impedance parameters of the monitor card.

Q: Does removing the ClickLoc connector under live -24 VDC loop conditions damage the probe coil?

A: No. The transducer is a passive induction loop component with no active semiconductors. Disconnecting the coaxial junction under live power does not cause physical degradation, though it results in an immediate monitor channel NOT OK trip status.

Q: How can target materials other than standard AISI 4140 steel be accommodated with this probe?

A: Utilizing non-magnetic or alternative stainless steel shafts modifies the eddy-current probe scaling behavior. Engineers must adjust the channel configuration scaling factor values within the 3500 configuration software or apply a manual calibration offset curve to correct the output metrics.