The Bently Nevada 22811-00-03-05-02 serves as the primary 22811-00-03-05-02 Proximity Probe utilized to execute static and dynamic distance measurements across 7200 Proximity Transducer System platforms. Operating on eddy-current technology, this hardware translates physical gap changes into proportional analog voltage signals to track shaft position, axial thrust, and vibration in rotating machinery.

Part Number Code Structure

The ordering configuration for the 22811-00-03-05-02 model breaks down into distinct mechanical and physical specifications:

• 22811: Core model identification for the 7200 Series 8 mm standard mount proximity probe.
• -00: Unthreaded length option.
• -03: Overall case length designation, representing 3.0 inches of threaded housing.
• -05: Total electrical length option, designating a 0.5-meter cable configuration.
• -02: Connector option, specifying a miniature coaxial connector with connector protector installed.

Technical Parameters & Mechanical Data

Eddy-Current Scaling and TSI Validation

Within rotating machinery monitoring (TSI) setups, the 22811-00-03-05-02 operates by generating an RF field from the probe tip. When matching this probe with a Proximitor, engineers must validate the gap voltage targets. A typical calibration target yields a scale factor of 200 mV/mil when mapping distances against AISI 4140 steel.

During calibration and zeroing steps, the physical gap must correspond to a target DC gap voltage of approximately -10 VDC to represent the center of the linear operating range. System length matching is mandatory; the probe lead must be paired with an appropriate extension cable to achieve a total electrical length of exactly 5.0 meters or 9.0 meters as required by the specific Proximitor module. Diverging from the matched system length alters the system's impedance and invalidates the scale factor.

Included Hardware Checklist

• 1 x Bently Nevada 22811-00-03-05-02 Proximity Probe (comprising 8 mm probe head, threaded case, and integrated 0.5-meter cable)
• 1 x Coaxial connector protector sleeve (installed)
• 2 x Hexagonal locknuts (fitted on threaded probe case)

Field Installation & Mechanical Alignment Guidelines

• Thread Engagement and Torquing Limits

  Ensure the 3/4-16 UNF threads engage cleanly with the mounting bracket. Tighten the locknuts to a recommended installation torque of 68 N m (50 ft lb). Do not exceed the maximum mechanical limit of 163 N m (120 ft lb) to prevent thread stripping or probe case distortion.

• Minimum Cable Bend Radius

  During routing, the flexible coaxial probe lead must never be bent sharper than a 25.4 mm (1.0 inch) radius. Kinking or over-bending degrades the internal shielding layer, altering cable capacitance and introducing electrical noise into the vibration readings.

• Target Spot Alignment

  The target shaft surface area must be at least three times the diameter of the probe tip (minimum 24 mm diameter) to prevent side-view interference. Ensure no metal surfaces lie within the lateral sensor field to prevent cross-talk or false calibration offsets.

Technical FAQ

• Can this 0.5-meter probe lead be connected directly to a Proximitor without an extension cable?

  No. The 7200 system requires a matched electrical length of either 5.0 meters or 9.0 meters. You must use a matching extension cable to reach the exact electrical length required by the Proximitor.

• How does targeting a non-steel shaft material affect the probe output?

  Targeting alloys like stainless steel or tungsten carbide changes the eddy-current resistance. This alters the default 200 mV/mil scale factor, requiring a custom-calibrated Proximitor module.

• What is the consequence of exceeding the 163 N m maximum torque spec during mounting?

  Exceeding the torque limit will deform the internal sensor housing, break the hermetic seal, or snap the threaded sleeve, resulting in permanent mechanical and electrical sensor failure.

• Is hot-swapping the probe cable connection permitted while the monitoring system is live?

  Yes, you can disconnect the coaxial extension cable while the system is powered, but the linked monitor channel will trip into a "Sensor Fault" or "NOT OK" status due to the loss of gap voltage.

• What is the standard target DC gap voltage for centering the probe in its linear range?

  The center of the 80 mils (2.0 mm) linear range corresponds to a gap voltage of approximately -10 VDC, measured at the Proximitor's output terminal.

• How do you prevent cross-talk between two adjacent 8 mm 7200 probes?

  Ensure a minimum physical separation distance of at least 40 mm between probe tips when mounted side-by-side, preventing their RF fields from overlapping and interfering.

• What environmental rating and chemical resistance does the probe tip have?

  The polyphenylene sulfide (PPS) tip is designed to resist typical industrial lubricating oils, moisture, and chemical washes, with operating thresholds exceeding 100 deg C.

• Why must the coaxial connector remain free of moisture and oil?

  Moisture or oil intrusion at the connection point introduces parallel resistance and alters overall capacitance, leading to erratic calibration drift and false high-vibration alerts.