Bently Nevada 30004-02-12-18-02 Eddy Current Proximity Probe Product Specification

30004-02-12-18-02 is a factory pre-calibrated eddy-current proximity probe under Bently Nevada’s 30004 product family, developed per API 670 standard for non-contact machinery condition monitoring. Matched with designated extension cable and compatible proximitor, it forms a complete TSI measurement loop to convert tiny metal shaft clearance variation into proportional linear DC voltage signals. It is primarily used to monitor radial vibration, axial thrust displacement and Keyphasor rotational speed of critical rotating equipment including steam turbines, centrifugal compressors, large feed pumps, blowers and generator sets in thermal power, petrochemical and metallurgical industries. Every finished probe passes factory capacitance matching test, continuity inspection, thermal cycling aging and connector sealing test before shipment to secure stable linearity and measuring precision under harsh industrial environments with oil mist, fluctuating temperature and complex electromagnetic interference. Original new products follow US manufacturing standards, while qualified refurbished probes undergo full parameter recalibration for field maintenance replacement.

The five-segment part number follows Bently’s standardized modular coding rules:30004 stands for core series code of 12mm outer diameter proximity probe with standard mounting thread, the general-purpose probe platform of Bently’s eddy current sensor system.02 defines exposed bare sensing tip length as 2mm, the uncovered detecting section from probe head to the start of mounting thread, suitable for compact narrow mounting holes on bearing housings with limited installation space.12 represents overall probe housing length of 120mm, designed for conventional shallow installation cavities of most standard equipment bearing pedestals.18 specifies factory pre-attached integral probe cable length of 1.8 meters; this fixed length is factored into total loop capacitance matching together with extension cable and proximitor, any random cutting or mismatched cable replacement will destroy preset impedance balance and cause measurement drift or non-linear error.02 indicates standard configuration: non-armored fluoropolymer outer cable jacket plus standard gold-plated stainless steel threaded connector at cable terminal, without customized metal armor or special modified plug structure. All specifications are fixed during production and cannot be altered arbitrarily on site.

The probe’s sensing head core is made of high-precision alloy wrapped with high-temperature resistant PPS insulation, which features stable dielectric constant, outstanding oil and chemical corrosion resistance to keep fixed capacitance amid varying ambient temperature and lubricant mist. Probe outer housing is precision-machined stainless steel with excellent mechanical strength, anti-rust and anti-high-temperature steam performance. Internal signal conductors adopt multi-strand oxygen-free copper to reduce high-frequency signal attenuation and improve anti-interference capacity. Intermediate insulation layer uses fluoropolymer with consistent dielectric property to satisfy eddy-current measurement requirements. Outer cable jacket is wear-resistant thermoplastic elastomer to resist on-site scratch, dust and oil erosion. The tail stainless steel connector is fitted with built-in rubber sealing ring to block moisture, metal dust and hydraulic oil from penetrating into inner wiring after mating with extension cable. The integral cable retains proper flexibility for convenient routing along equipment and cable trays without insulation cracking within rated bending radius.

This probe works with matched proximitor powered by -17.5VDC ~ -26VDC negative DC supply. The full measurement loop consisting of probe, certified extension cable and proximitor maintains factory-calibrated fixed sensitivity, with effective frequency response from 0Hz to 10kHz to capture slow static axial displacement and high-frequency dynamic radial rotor vibration.

Permitted continuous operating ambient temperature ranges from -40℃ to +120℃, fitting low-temperature outdoor installation and high-temperature layout near hot equipment casings; storage temperature spans -55℃ to +95℃ under dry non-condensing surroundings. Working relative humidity is limited between 5%RH and 95%RH with no internal condensation allowed to avoid insulation deterioration and inner short circuit. When installed above 1000 meters altitude, inspection frequency for cable and connectors shall be increased properly due to reduced heat dissipation at thin air condition. The probe withstands regular industrial vibration of 10Hz~60Hz; long-term operation in environments with strong corrosive gas, heavy chemical vapor and accumulated conductive metal powder is forbidden to extend service life.

30004-02-12-18-02 probes are widely mounted on bearing housings of large rotating machinery in power plants, refineries and metallurgical workshops, feeding real-time gap data to Bently 3500 monitoring rack, DCS or PLC systems for over-limit pre-alarm and emergency trip interlock to prevent catastrophic mechanical damage caused by excessive rotor vibration or abnormal axial shifting.

During regular maintenance, inspect housing surface integrity, outer jacket abrasion and connector tightness periodically to avoid intermittent signal loss caused by loose connection or oil infiltration via damaged sheath. For breakdown replacement, only spare probe with identical full part number can be used; mismatched integral cable length or tip dimension will change total loop capacitance and lead to inaccurate measuring data. All refurbished replacement probes complete full capacitance calibration, load aging and alternating high-low temperature shock test per original factory standards before delivery to ensure consistent performance with brand-new originals.