Description
The Bently Nevada 330104-04-10-10-02-05 is a 3300 XL 8mm proximity probe designed for non-contact eddy current measurement of shaft vibration, axial position, and speed in critical rotating machinery. Operating as a component of the 3300 XL Proximitor Sensor system, it converts the physical distance between the probe tip and a conductive target into a linear voltage signal. This specific configuration features a 3/8-24 UNF unthreaded length, fractional overall case length, a 1.0-meter total length, a miniature coaxial connector with a connector protector, and agency approval certifications.
Technical Specifications & Part Number Breakdown
The specific model code 330104-04-10-10-02-05 determines the mechanical and electrical variables of this 8mm probe assembly:
| Option Code | Parameter | Value / Specification |
| 330104 | Product Series | 3300 XL 8mm Proximity Probe, 3/8-24 UNF thread |
| -04 | Unthreaded Length | 0.4 inches (10 mm) |
| -10 | Overall Case Length | 1.0 inch (25 mm) |
| -10 | Total Length | 1.0 meter (3.3 feet) |
| -02 | Connector Option | Miniature coaxial ClickLoc connector with connector protector |
| -05 | Agency Approval | Multiple Approvals (ATEX, IECEx, CSA, Class I Div 1/Zone 0) |
Mechanical & Material Specifications
| Parameter | Value / Specification |
| Probe Tip Material | Polyphenylene sulfide (PPS) |
| Probe Case Material | AISI 303 stainless steel (SST) |
| Cable Type | 75 \Omega coaxial, high-flex, coaxial with Tefzel insulation |
| Linear Range | 2.0 mm (80 mils), starting at approximately 0.25 mm (10 mils) from the tip |
| Scale Factor | 7.87 V/mm (200 mV/mil) when combined with a 3300 XL Proximitor |
| Operating Temperature | −51 to +177°C (−60 to +351°F) for probe and cable |
| Minimum Bend Radius | 25.4 mm (1.0 in.) for extension cable and probe cable |
| Torque Rating | 11.2 N·m (100 in·lb) maximum |
Commercial and Logistics Terms
- Condition: New Original (Factory Sealed)
- Warranty: 12-Month Comprehensive Warranty
- Availability: In Stock / Available for Order
- Lead Time: Ships within 1 to 3 business days from order confirmation
- Pricing: Price subject to market conditions; contact us for a firm quote
Engineering Overview & Integration Notes
In machinery protection applications (API 670 compliant), the 330104 probe provides critical inputs to monitoring systems like the Bently Nevada 3500 series. Correct installation dictates strict adherence to target material and clearance rules.
Target Material & Calibration
The probe is factory-calibrated for AISI 4140 steel. Using this probe with alternative shaft materials (such as 17-4 PH stainless steel, Inconel, or chrome-plated journals) will alter the electrical conductivity and magnetic permeability, causing a shifted scale factor. Always verify the target material and modify the Proximitor configuration or apply calibration scaling factors if required.
Total System Length Matching
The -10 option denotes a 1.0-meter total probe length. This probe must be matched with an extension cable and Proximitor sensor that achieve the system’s total designated electrical length (typically 5.0 meters or 9.0 meters).
- Example configuration: A 1.0-meter probe requires an 8.0-meter extension cable to operate correctly with a 9.0-meter Proximitor sensor.
- Constraint: Mixing 5.0-meter and 9.0-meter components degrades the linearity of the system and introduces substantial measurement errors.
Physical Installation & Gap Voltages
When mounting the probe in a bearing housing or bracket, ensure a minimum side clearance of 2 or more probe tip diameters (at least 16 mm) from surrounding steel structure to prevent cross-talk and side-loading errors. Set the mechanical position using a digital voltmeter measuring the DC gap voltage at the Proximitor output terminal. A typical baseline center-gap setting is −10.0 V DC, corresponding to the middle of the linear range.
Field Note: The -02 connector option includes a pre-installed connector protector. Do not remove this during routing. The protector prevents fluid ingress (lubrication oil, moisture) into the coaxial junction, which is a leading cause of signal degradation and intermittent machine trip alerts.
Frequently Asked Questions
Can I shorten or splice the 1.0-meter cable if it is too long for my terminal box?
No. Never cut, splice, or shorten the coaxial cable on an eddy current proximity probe. The total electrical length of the probe cable is an intrinsic part of the tuned RF circuit. Modifying the physical length changes the circuit impedance and permanently corrupts the calibration.
What is the purpose of the 0.4-inch unthreaded length (-04 option)?
The unthreaded portion prevents the thread from binding or stripping inside mounting brackets or counterbored holes during installation. It allows the probe to slip cleanly into the initial section of the mounting port before the threads engage, easing alignment inside tight bearing housings.
How do I verify if the probe winding is damaged using a multimeter?
Disconnect the probe from the extension cable. Measure the resistance between the center pin and the outer shell of the coaxial connector. For a 1.0-meter probe, the typical internal DC resistance should register between 4.0 \Omega and 11.0 \Omega (verify with the exact OEM datasheet for nominal target values). An open circuit (\infty resistance) or a dead short to the case indicates a damaged coil or broken internal conductor.
