June 05, 2026

Bently Nevada 21504-062-096-05-02 Eddy Current Proximity Probe Product Specification

21504-062-096-05-02 is factory pre-calibrated 8mm standard front-mounted eddy current proximity probe belonging to Bently Nevada 7200 series transducer product line, developed to match original supporting proximitor driver and 75-ohm impedance-matched extension cable to constitute a complete non-contact displacement measuring system complying with API 670 industry standard for rotating machinery protection. Based on eddy current induction working principle, the probe converts tiny clearance variation between sensing tip and conductive metallic rotor target into continuous linear analog voltage output signals, which are transmitted to 7200 or 3500 rack-mounted monitoring modules to implement real-time online measurement of equipment radial shaft vibration, axial thermal displacement and Keyphasor rotational speed trigger signals. Widely equipped on steam turbines, gas turbines, centrifugal compressors and large generator sets within power, petrochemical and metallurgical industries, it provides over-limit alarm output and emergency shutdown interlock signal for core unit safe running control. Each finished probe undergoes strict full-range linear calibration, high-low temperature alternating aging cycling and full epoxy hermetic encapsulation inspection before factory delivery to guarantee stable measuring accuracy under severe on-site working conditions including high bearing housing ambient temperature, pervasive lubricating oil mist and complex electromagnetic interference from high-power cables and frequency conversion drive equipment.

Description

Bently Nevada 21504-062-096-05-02 Eddy Current Proximity Probe Product Specification

1. Product Overview

2. Part Number Definition Breakdown

All coding segments follow Bently Nevada unified 7200 series proximity probe naming specification; base serial code 21504 represents standard 8mm diameter front-thread proximity probe specially customized for 7200 transducer system platform. The segment 062 stands for 62mm fixed unthreaded exposed tip length reserved for deep embedded installation of thick-wall bearing pedestal and special narrow space mounting hole layout; segment 096 defines 960mm total threaded housing length to adapt ultra-deep installation hole requirement unavailable for conventional short-body probes; segment 05 specifies factory integrated fixed coaxial cable length of 0.5 meter permanently molded together with probe main body during production; final suffix code 02 refers to standard miniature male coaxial terminal connector pre-installed at cable tail for plug-type connection with original calibrated matched extension cable. Any modification of digital coding will change probe mechanical dimension or factory preset electrical calibration parameter, random on-site replacement with non-same part number product will damage full-loop matching calibration and cause measuring deviation or unexpected protection trip of monitoring channel.

3. Core Functional Characteristics

Probe threaded housing and sensing head are precision machined from high-density anti-corrosion stainless steel material with excellent erosion resistance against bearing lubricant oil and weak corrosive vapor inside sealed bearing cavity. Internal induction coil is fully filled and fixed with high-temperature resistant epoxy potting adhesive to eliminate internal air gap, effectively avoid coil displacement and inter-turn short-circuit failure caused by long-term equipment running vibration and ambient temperature fluctuation. Attached 0.5m integral coaxial cable adopts standard 75-ohm controlled impedance structure with over 95% coverage dense tinned copper braided shielding layer to effectively restrain external electromagnetic crosstalk during on-site signal transmission. Field cutting, joint splicing and arbitrary replacement of original cable and tail connector are strictly prohibited, all manual physical changes will permanently invalidate factory preset full-set calibration data of the transducer system. Extra-long customized tip and threaded body design is exclusively optimized for ultra-deep buried installation environment of special bearing seat structure. Built-in open-circuit and short-circuit self-diagnosis function rapidly feeds back abnormal wiring state through obvious output voltage offset to simplify daily field circuit troubleshooting work. Complete measuring linearity of the whole system can only be maintained by original matching of this probe, designated calibrated extension cable and supporting proximitor preamplifier.

4. Electrical and Metrological Specifications

Matched supporting proximitor supplies regulated negative DC working voltage ranging from -17.5VDC to -26VDC, and -24VDC is the standard rated operating voltage adopted in practical industrial site. Factory fixed calibrated sensitivity is 7.87V/mm (200mV/mil) with standard AISI4140 carbon steel as calibration target material, full measuring range linearity error is controlled within ±5% complying with API670 specification requirement. Valid linear measuring range covers 0mm~2.0mm, which satisfies routine radial vibration and short-stroke axial clearance detection of most large industrial rotating shafts. Effective frequency response range covers DC to 10kHz, synchronously collecting low-frequency static thermal expansion drift signal and high-frequency dynamic shaft vibration signal. Recommended pre-installation gap is set at middle position of linear measuring range to ensure stable bias working point for long-time uninterrupted equipment operation.

5. Environmental Working Parameters

Continuous allowable operating temperature of probe sensing part ranges from -40°C to +150°C to adapt high-temperature installation surroundings near heated bearing housings and turbine cylinder casings. Spare part storage temperature is controlled between -55°C~+85°C under dry non-condensation storage environment; applicable working relative humidity ranges from 5%RH to 95%RH without dew accumulation on probe outer casing and cable outer sheath surface. The probe can withstand routine mechanical vibration of 10Hz~2kHz generated by adjacent operating rotating equipment. Long-term continuous soaking in corrosive chemical liquid, acid mist and persistent high-temperature steam environment is forbidden to prevent outer shell corrosion and internal insulating layer aging damage. For installation location above altitude 1000 meters, shorten regular equipment inspection cycle properly.

6. Installation and Routine Maintenance Guidance

Cut off total power supply of whole monitoring loop before field installation, screw the customized long-body threaded probe into pre-reserved deep threaded hole of bearing pedestal or special customized mounting fixture, adjust pre-set installation clearance to rated design value and lock fastening nut tightly to prevent installation looseness induced by long-term equipment running vibration. During field wiring construction, separate probe signal cable routing away from high-current AC power cable and inverter output wiring to reduce cross electromagnetic coupling interference. Avoid sharp small-radius bending, excessive stretching and heavy mechanical extrusion on cable body to prevent inner conductor breakage and impedance abnormal drift. Within regular equipment maintenance cycle, periodically check cable outer jacket for oil corrosion, abrasion and cracking damage, and inspect locking tightness of tail terminal connector. When probe performance failure needs field replacement, only spare part with identical full part number 21504-062-096-05-02 can be directly replaced. All replacement probes complete full electrical performance testing and alternating temperature aging screening before factory outbound delivery to guarantee full interchangeability inside original vibration monitoring measuring loop.

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