Bently Nevada 330908-39-71-05-01-00 NSv Probe

Bently Nevada 330908-39-71-05-01-00 3300 NSv Proximity Probe

Product Introduction

The Bently Nevada 330908-39-71-05-01-00 represents the advanced 3300 NSv series of proximity probes. Specifically, this model excels at non-contacting vibration and position measurement on critical rotating machinery. Furthermore, it offers superior chemical resistance compared to older 3300 RAM probes, making it ideal for process compressor applications. The side-view characteristics also outperform the 3000-series 190 probe when gapped at the same target distance. This particular variant comes with a 0.5-meter total cable length and a 3.9-inch unthreaded section.

Technical Specifications

The 330908-39-71-05-01-00 sensor features a probe case constructed from AISI 304 stainless steel and a tip made of Polyphenylene sulfide (PPS). Its unthreaded length option of -39 provides a 3.9-inch section, while the -71 overall case length delivers a 7.1-inch housing. The total length option -05 indicates a 0.5-meter (20-inch) cable. Meanwhile, the connector option -01 includes a miniature coaxial ClickLoc connector with a protector for added security. The agency approval option is -00, meaning no special certifications are required. The probe cable uses a 75 Ω coaxial design with FEP insulation, ensuring reliable signal transmission.

Electrical Performance Parameters

For the 3300 NSv probe with a 0.5-meter length, the DC resistance from the center conductor to the outer conductor (RPROBE) measures 4.0 ± 0.5 ohms. The linear range spans 1.5 mm (60 mils), starting at approximately 0.25 mm (10 mils) from the target and extending to 1.75 mm (70 mils), corresponding to roughly -1 to -13 Vdc. The recommended gap setting is 1.0 mm (40 mils) . Additionally, the Incremental Scale Factor (ISF) is 7.87 V/mm (200 mV/mil) with a tolerance of +12.5%/-20% including interchangeability error. The deviation from the best-fit straight line (DSL) is less than ±0.06 mm (±2.3 mils) . The frequency response reaches 0 to 10 kHz at +0, -3 dB typical with up to 305 meters of field wiring.

Extension Cable and Wiring Specifications

The extension cable exhibits a center conductor DC resistance of 0.220 Ω/m and a shield resistance of 0.066 Ω/m. Its typical capacitance is 69.9 pF/m. For field wiring, we recommend using three-conductor shielded triad cable with a conductor size of 0.2 to 1.5 mm² (16 to 24 AWG). The maximum field wiring length between the Proximitor Sensor and the monitor is 305 meters (1,000 feet) . However, please consult the frequency response graphs for signal rolloff information when using longer wiring runs.

Mechanical and Environmental Ratings

The 330908-39-71-05-01-00 probe operates and stores within a temperature range of -52°C to +177°C (-62°F to +351°F) . The minimum bend radius for the cable is 25.4 mm (1.0 inch), whether armored or not. For the probe case torque on 3/8-24 threads, the maximum rated value is 33.9 N•m (300 in•lb) , while the recommended torque is 11.3 N•m (100 in•lb) . The connector-to-connector torque maximum is 22.6 N•m (200 in•lb) with a recommended setting of 7.5 N•m (66 in•lb) . The maximum thread engagement length is 0.563 inches. The Viton O-ring effectively seals differential pressure between the tip and case.

Target Requirements and Installation Guidance

For optimal performance with the 3300 NSv probe, the minimum recommended target diameter is 13 mm (0.5 inches) . However, the absolute minimum is 8.9 mm (0.35 inches). When measuring axial position on shaft diameters smaller than 13 mm, the scale factor may change. To mitigate this effect, reduce the gap between the probe and target. During installation, first tighten the probe finger-tight, then apply the recommended torque of 11.3 N•m using a calibrated wrench. The maximum torque for the probe case is 33.9 N•m , so avoid exceeding this limit. Also, ensure the thread engagement does not surpass 0.563 inches.

Packaging List

• Bently Nevada 330908-39-71-05-01-00 Proximity Probe (1 unit)

• Connector protector (installed on the ClickLoc connector)

• Protective tip cap

• Installation instruction sheet

Frequently Asked Questions (FAQ)

1. Is the Bently Nevada 330908-39-71-05-01-00 compatible with older 3300 RAM systems?
Yes, the 330908-39-71-05-01-00 probe is fully mechanically and electrically interchangeable with the previous 3300 RAM probes and extension cables. This allows for seamless upgrades without changing your existing infrastructure.

2. What is the purpose of the connector protector on this 3300 NSv probe?
The connector protector on the ClickLoc connector provides an additional layer of mechanical protection and environmental sealing. It helps prevent contamination and damage to the connector interface during installation and operation.

3. Can this probe be used with shaft diameters smaller than 13 mm?
While the probe will function, axial position measurements on shafts under 13 mm in diameter may experience a change in the scale factor. We recommend reducing the gap setting to help limit this variation, and we suggest consulting the technical manual for specific guidance.

4. Why are these 3300 NSv probes not pressure tested before shipment?
Bently Nevada does not perform pressure testing as a standard procedure because application pressures vary widely. The Viton O-ring seal is designed for differential pressure sealing, but for custom requirements, you can contact their custom design department for a specific test.

5. What is the maximum field wiring length for the 3300 NSv system?
The system supports field wiring up to 305 meters (1,000 feet) between the Proximitor Sensor and the monitor. However, at longer lengths, the high-frequency response may roll off, so we advise reviewing the frequency response data for your specific application.