Bently Nevada 3300 5mm Proximity Probe – 330170-00-08-20-02-05

Overview: A Compact Alternative for Space-Constrained Mounting

The Bently Nevada 3300 5mm Proximity Probe, part number 330170-00-08-20-02-05, is a member of the 3300 5mm Proximity Transducer System, offering a smaller probe diameter than the standard 8mm probe family while remaining backward-compatible and interchangeable with 3300 XL 8mm extension cables and Proximitor sensors. This compact form factor makes the 5mm probe the preferred choice in applications where an 8mm probe is simply too large for the available mounting space on the machine.

As a trusted supplier of Bently Nevada machinery protection instrumentation, Seven Star LLC sources and supplies the 3300 5mm proximity probe to refineries, gas processing plants, and power generation facilities across Oman and the wider GCC. Because 5mm probes must be correctly matched with compatible cable and Proximitor sensor electrical lengths, Seven Star LLC helps engineering teams confirm the correct combination for their specific machine and mounting constraints.

Measurement Principle

Like the 8mm probe family, the 3300 5mm probe operates on the eddy current principle, generating a radio-frequency field at the probe tip that loses energy in proportion to the gap distance to a nearby conductive target. The Proximitor sensor demodulates this energy loss into an output voltage that varies linearly with the distance between probe tip and target, supporting both static (position) and dynamic (vibration) measurement on fluid-film bearing machines, as well as Keyphasor reference and speed measurement applications.

The system requires that the electrical length of the proximity probe plus the electrical length of the extension cable equal the electrical length of the Proximitor sensor, a matching requirement that applies across the entire 3300 and 3300 XL probe family regardless of probe diameter. This consistent electrical-length principle is what allows the 5mm probe to remain fully interchangeable with the broader 3300 XL 8mm system components, simplifying spares planning for sites running mixed probe diameters.

Engineering Design of the 3300 5mm Probe

The 3300 5mm probe is constructed with a polyphenylene sulfide (PPS) probe tip and an AISI 303 or 304 stainless steel case, with a fluoroethylene propylene (FEP) insulated probe cable providing chemical and thermal resistance in demanding process environments. The probe is rated for an operating temperature range of -35°C to +177°C (-31°F to +351°F), with a caution that sustained exposure below -34°C may cause premature pressure seal failure.

Power requirements for the 5mm probe family are typically -17.5 Vdc to -26 Vdc at up to 12 mA, with voltages above -23.5 Vdc reducing the effective linear range, so a recommended supply voltage of around -24 Vdc is used for best performance. The -05 suffix on this part number indicates CSA, ATEX, and IECEx hazardous-area approvals, extending the probe’s application to classified areas in refineries and offshore facilities where the standard 8mm probe cannot physically be accommodated.

Calibration, Linear Range and Target Requirements

The Bently Nevada 3300 5mm Proximity Probe is factory calibrated to a typical incremental scale factor of 7.87 V/mm (200 mV/mil) ±6.5 %, the same sensitivity used across the 3300 XL 8 mm family, and it delivers that sensitivity over a linear range of 0.25 to 2.3 mm (10 to 90 mils) with a recommended installed gap of 1.27 mm (50 mils). Deviation from linearity is typically better than ±0.038 mm (±1.5 mil), and frequency response runs from 0 to 10 kHz at +0/–3 dB with up to 305 metres (1000 feet) of field wiring — enough headroom for the long cable runs between a compressor skid and a machinery protection rack in a typical Omani gas plant.

Calibration is referenced to an AISI 4140 steel target, so shafts of a different alloy require a factory or field recalibration if absolute gap accuracy matters. The probe needs a minimum flat target of 15.2 mm (0.6 in) diameter, and a shaft diameter of at least 50.8 mm (2 in) with 76.2 mm (3 in) or larger recommended, to avoid side-loading of the eddy current field. The 5.2 mm probe tip is offered on 1/4-28 UNF or M8×1 threaded cases, and the probe terminates in a gold-plated miniature coaxial ClickLoc connector with a 50 Ω output impedance, matching the connector standard used throughout the 3300 XL system.

Key Features

The Bently Nevada 3300 5mm Proximity Probe delivers proven eddy current sensing in a compact form factor. Key characteristics include:

• Smaller probe diameter than the 8mm family, suited to space-constrained mounting locations.
• Full backward compatibility and interchangeability with 3300 XL 8mm extension cables and Proximitor sensors.
• Eddy current sensing principle for non-contact position and vibration measurement.
• PPS probe tip material with AISI 303/304 stainless steel case and FEP-insulated cable.
• Operating temperature range of -35°C to +177°C.
• CSA, ATEX, and IECEx approvals for hazardous-area installation (per -05 suffix).
• Supports both vibration/position measurement and Keyphasor reference/speed measurement applications.

Industrial Applications

The 3300 5mm proximity probe is deployed on fluid-film bearing machines where mounting space is limited, including smaller turbines, compressors, and rotating equipment where an 8mm probe bore cannot be accommodated in the bearing housing design. It performs the same continuous radial vibration and shaft position monitoring role as the larger 8mm probe family, making it a valuable option for retrofit projects on compact machinery.

Seven Star LLC supports refinery instrumentation teams, power generation engineers, and rotating equipment maintenance departments across Oman, Muscat, Sohar, and the broader GCC region with sourcing of Bently Nevada 3300 5mm proximity probes, helping plants maintain machinery protection coverage even on space-constrained equipment.

Technical Specifications

The table below summarizes the core specifications of the Bently Nevada 3300 5mm Proximity Probe as supplied by Seven Star LLC.

Request a Quote for Bently Nevada 3300 5mm Proximity Probe – 330170-00-08-20-02-05

Seven Star LLC supplies the Bently Nevada 3300 5mm Proximity Probe with datasheet documentation and regional technical support. Contact our instrumentation division for a formal B2B quotation, to confirm the correct matched probe, cable, and Proximitor sensor combination for your machine, or to obtain the complete technical datasheet.Seven Star LLC supplies this item on request with the manufacturer documentation, and availability and lead time are confirmed at quotation.

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See also: Bently Nevada 177230 Seismic Transmitter; Bently Nevada 3500/61 Temperature Monitor with Recorder Outputs.