The Bently Nevada 31000-16-05-00-070-03-02, also cataloged as the 31000 Proximity Probe Housing Assembly, operates as a dedicated hardware component for protecting and positioning proximity probes within machinery monitoring platforms.

Suffix Selection Matrix

The configuration options of this explosion-proof housing assembly are specified by its individual model suffixes:

• 31000: Base model designation for the standard Proximity Probe Housing Assembly.
• -16: Integrates a 3300 XL 8 mm probe with coaxial connector.
• -05: Selects a probe cable length of 0.5 meter (20 inches).
• -00: Specifies no standoff adapter.
• -070: Configures a probe penetration length of 7.0 inches (177.8 mm).
• -03: Includes two plugs, one 3/4-14 NPT fitting, one 3/4-14 to 1/2-14 NPT stainless steel reducer, and one cable seal grip with three sizing grommets.
• -02: Selects a 3/4-14 NPT mounting thread option.

Hardware Specifications

Eddy-Current Probe Scaling and Rotor Dynamics Integration

The integrated 3300 XL 8 mm probe within the 31000-16-05-00-070-03-02 housing employs eddy-current probe scaling to measure static and dynamic shaft displacement. This displacement is translated into a precise voltage output relative to the gap between the probe tip and the target shaft. During mechanical calibration, field technicians perform a gap voltage validation (-10 VDC target representing the physical center of the linear range) to align the rotor dynamics measurement system.

To prevent cross-talk suppression failures when multiple probe systems are installed in close physical proximity, the housing ensures proper spatial separation and structural shielding. This mechanical isolation preserves signal accuracy across the standard 3300 XL -24 VDC Proximitor loop.

Ordering Info

• 1 x Bently Nevada 31000-16-05-00-070-03-02 Housing Assembly (with integrated 3300 XL 8 mm probe)
• 2 x Internal sealing plugs
• 1 x 3/4-14 NPT fitting
• 1 x 3/4-14 to 1/2-14 NPT stainless steel reducer
• 1 x Cable seal grip assembly with 3 sizing grommets (1/8 to 3/16 inch, 1/4 to 5/16 inch, and 5/16 to 3/8 inch sizes)

Field Installation Guidelines

• Thread Mechanical Verification Inspect the 3/4-14 NPT mounting thread before installation. Ensure thread cleanliness and apply suitable high-temperature thread sealant to achieve an environmental barrier. Engage at least 5 full threads to maintain explosion-proof enclosure ratings.
• Penetration Depth Configuration Confirm that the 7.0 inch probe penetration depth does not cause mechanical interference with the target shaft or internal components of the bearing housing during thermal expansion.
• Cable Gland and Grommet Fitting Select the rubber grommet that matches the external diameter of your field cable. Tighten the cable seal grip dome nut to compress the grommet fully, preventing moisture or oil migration into the housing cavity.

Frequently Asked Questions

• How is the target gap voltage validated during the installation of this assembly?

  A voltmeter is connected to the Proximitor monitor loop to read the output voltage, which must be adjusted via physical rotation of the probe to reach a target of -10 VDC.

• What is the purpose of the 3/4-14 to 1/2-14 NPT stainless steel reducer?

  The reducer allows the housing assembly's larger 3/4-14 NPT conduit entries to interface with standard 1/2-14 NPT field conduit runs.

• Does this assembly support hot-swap replacement of the internal probe?

  Yes, the housing cover can be removed to access and replace the integrated probe assembly without unthreading the main housing body from the machine case.

• Which target material is required for the integrated 3300 XL 8 mm probe?

  The probe is calibrated for AISI 4140 steel. Using other target materials requires re-calibration due to variances in eddy-current probe scaling.

• How do the grommets in the cable seal grip prevent moisture ingress?

  The three interchangeable grommets squeeze around cable sizes from 1/8 to 3/8 inches, creating a tight hermetic barrier inside the cable gland.

• What is the standard operating temperature range for the integrated probe within the housing?

  The internal proximity probe is designed to operate reliably within standard industrial environments ranging from -51 to +177 deg C.

• Can this proximity probe housing be used in hazardous locations?

  Yes, the 31000 housing is designed to meet explosion-proof and flameproof standards when installed with the appropriate NPT fittings and seals.

• Does the lack of a standoff adapter affect the structural stability?

  No, the -00 option provides a direct, low-profile mount to the machine casing, minimizing overhang and increasing resistance to external high-frequency vibrations.