330105-02-12-10-02-00 is a reverse mount eddy current probe from the Bently Nevada 3300 XL series, with a total length of 1.0 meter (3.3 feet). This model features 3/8-24 UNF threads, 0.2‑inch unthreaded length, 1.2‑inch overall case length, a standard ClickLoc coaxial connector, and standard FEP‑insulated cable. It does not include armor or hazardous area approvals. Its most notable feature is the reverse mount design, where the probe is installed from inside the equipment outward, with thread orientation opposite to standard probes. This design is ideal for installations through bearing housings or casings from the inside, simplifying installation and reducing leakage risks.
With a total length of 1.0 m, this probe is typically used with a 4.0‑meter extension cable (e.g., 330130-040-00-00) and a 5‑meter Proximitor Sensor (e.g., 330180-50-00) to form a complete 5‑meter system (1.0 m probe + 4.0 m extension cable = 5 m system). This configuration is suitable for installations where the Proximitor Sensor is mounted close to the equipment (e.g., in a junction box). The reverse mount design is particularly suitable for turbomachinery bearing housings where internal routing is required.
Model Breakdown: 330105-02-12-10-02-00 Configuration Details
Following Bently Nevada’s part number coding system (refer to datasheet Pages 14, 36), the fields in this model number represent the following:
Field | Code | Parameter | Description |
Base Model | 330105
| 3300 XL 8 mm Reverse Mount Probe, 3/8-24 UNF thread, without armor | For installation from inside equipment outward, imperial thread |
Unthreaded Length (A) | 02
| 0.2 inches | Distance from probe tip to start of thread (fixed for reverse mount probes) |
Overall Case Length (B) | 12
| 1.2 inches | Total threaded length (fixed for reverse mount probes) |
Total Length Option (C) | 10
| 1.0 meter (3.3 ft) | Total probe cable length (including connector); for 5 m systems |
Connector & Cable Option (D) | 02
| Miniature coaxial ClickLoc connector, standard cable | Standard FEP‑insulated cable, gold‑plated ClickLoc connector, no connector protector |
Agency Approval (E) | 00
| Not required | Standard industrial version for non‑hazardous areas |
Key Configuration Note: This model is a reverse mount probe, with thread orientation opposite to standard probes, designed for installation from inside the equipment outward. The unthreaded length (0.2 in) and case length (1.2 in) are fixed for this reverse mount series. The 1.0 m total length is for 5‑meter systems (paired with a 4.0 m extension cable). This model does not include armor, connector protectors, or hazardous area approvals, making it suitable for standard industrial environments.
Reverse Mount Features
What is a Reverse Mount Probe?
Standard probes are installed from outside the equipment inward, with threads at the front of the probe case and the probe tip facing inward. In contrast, a reverse mount probe has threads at the rear of the probe case; the probe is installed from inside the equipment outward, with the tip facing outward (typically toward the rotating shaft). This design offers several advantages:
Simplified bearing housing installation: The probe can be routed from inside the bearing housing outward, reducing leak paths by eliminating external threaded adapters.
Easier sealing: Reverse mounting makes it easier to achieve oil sealing, preventing lubricant leakage along the probe.
Suitable for space‑constrained exteriors: When external space is limited for standard probe installation, reverse mounting solves the problem from inside.
Fixed dimensions: Unthreaded length and case length are fixed for reverse mount probes (0.2 in and 1.2 in), simplifying selection.
No Armor or Connector Protector on This Model
This model does not include pre-installed armor or connector protectors. The cable is standard FEP, and the connector is exposed to the environment. It is suitable for dry, clean installations. If environmental sealing or mechanical protection is required, select a reverse probe with appropriate options (e.g., FluidLoc cable option 12).
Selection Tip: Reverse mount probes are often used in turbomachinery bearing housings. Connector protectors are strongly recommended to prevent oil mist ingress.
Application Scenarios & Selection Guide
330105-02-12-10-02-00 is suitable for the following typical applications:
Precise Total Length Matching for 5‑Meter Systems + Reverse Mount: Paired with a 4.0 m extension cable (e.g., 330130-040-00-00) and a 5 m Proximitor Sensor (e.g., 330180-50-00) to form a complete 5‑meter monitoring system. Ideal for installations where the Proximitor Sensor is mounted close to the equipment (e.g., in a junction box) and the probe needs to be installed from inside the equipment outward.
Turbomachinery Bearing Housings: Steam turbines, compressors, and gas turbines often require internal probe mounting. Reverse mount design allows the probe to exit the bearing housing from inside, avoiding external sealing issues.
Leak‑Prone Applications: When used with appropriate seals, reverse mount probes effectively prevent lubricating oil leakage along the probe threads.
Space‑Constrained External Environments: When external space is insufficient for standard probe installation, reverse mounting provides an internal solution.
Standard Industrial Environments: No armor, no hazardous area approvals – suitable for non‑hazardous, dry, clean installations.
Selection Notes:
Total Length Matching: Probe length + extension cable length = Proximitor Sensor total system length (5 m or 9 m). This 1.0 m probe must be used with a 4.0 m extension cable to form a 5‑meter system.
System Accuracy: This model is used in a 5‑meter system, with DSL < ±0.025 mm, which is better accuracy than 9‑meter systems. Suitable for high‑precision applications.
Installation Direction: Reverse mount probes are installed from inside the equipment outward. Ensure sufficient internal access for installation. Thread engagement should not exceed the datasheet maximum (0.563 inches).
Sealing Requirements: Use appropriate gaskets or O‑rings at the probe mounting point to prevent oil leakage.
Ambient Temperature: Standard probe is rated to +177°C. For higher temperatures, select an ETR high‑temperature reverse mount probe (330195 series).
Hazardous Area Requirements: If explosive gas atmospheres are present, select the version with hazardous area approvals (e.g., 330105-02-12-10-02-05).
Connector Protection: In oil mist environments, connector protectors (order separately) are strongly recommended.
Mechanical Dimensions & Installation
Probe Tip Diameter: 8.0 mm (0.31 in)
Thread Specification: 3/8-24 UNF-2A (reverse thread); recommended lock nut torque for first three threads: 7.5 N·m (66 in·lbf)
Overall Case Length: 1.2 in (30.5 mm)
Unthreaded Length: 0.2 in (5.1 mm)
Cable Outer Diameter: 3.68 mm (0.145 in) maximum
Connector Outer Diameter: 7.24 mm (0.285 in) maximum
Minimum Bend Radius: 25.4 mm (1.0 in)
Installation Tips: Before installation, inspect the mounting hole threads for cleanliness and depth. Reverse mount probes are installed from inside the equipment outward, with the lock nut tightened from the outside. Thread engagement should not exceed 0.563 inches. Use the recommended lock nut (part number 04301007) and tighten to the specified torque (7.5 N·m for the first three threads). Set the probe gap to the recommended -9 Vdc (approx. 1.27 mm), monitored via the Proximitor Sensor output voltage.
Related Products & Compatible Configurations
This probe is typically used with the following products to form a 5‑meter system:
Companion Product | Recommended Model | Description |
Extension Cable | 330130-040-00-00 | 4.0 m standard cable, forms 5 m system |
Proximitor Sensor | 330180-50-00 | 5 m system panel‑mount Proximitor, no approvals |
Lock Nut | 04301007 | 3/8-24 lock nut with safety wire holes |
Connector Protector | 40180-02 (or 40113-02) | Recommended for oil mist environments |
For other configurations, refer to the following reverse mount probe options:
Model | Thread | Unthreaded Length | Case Length | Total Length | Cable Option | Approvals | Application |
330105-02-12-10-02-00 | 3/8-24 | 0.2" | 1.2" | 1.0 m | Standard | None | Current model, 5 m system, reverse mount |
330105-02-12-10-12-00 | 3/8-24 | 0.2" | 1.2" | 1.0 m | FluidLoc | None | Reverse mount with oil leak prevention |
330105-02-12-10-02-05 | 3/8-24 | 0.2" | 1.2" | 1.0 m | Standard | ATEX/IECEx | Hazardous area reverse mount |
330106-05-30-10-02-00 | M10×1 | 5 mm | 30 mm | 1.0 m | Standard | None | Metric thread reverse mount version |
Matching Extension Cable: This probe must be used with a 4.0‑meter extension cable (e.g., 330130-040-00-00) to form a complete 5‑meter system.
Inquiry & Technical Support
330105-02-12-10-02-00 is a commonly used reverse mount model in the Bently Nevada product line, designed for 5‑meter systems requiring internal probe installation. For pricing, lead time, or technical drawings, please contact us:
Online Inquiry: Click the “Request a Quote” button and provide the model number for a prompt response.
Technical Support: If you need assistance verifying whether this configuration meets your reverse mount installation requirements, please describe the installation environment (equipment type, oil mist, available space, etc.) and we will help recommend the optimal configuration.
