Bently Nevada 21000-16-05-15-060-03-02 Armored Eddy Current Probe Assembly Product Specification

The 21000-16-05-15-060-03-02 is a factory pre-calibrated heavy-duty armored eddy current proximity probe assembly belonging to Bently Nevada 21000 series armored installation product line, designed for harsh industrial working conditions including high temperature bearing housings, dense lubricating oil mist and deep bore embedded installation on bearing pedestals of critical rotating equipment. This integrated probe unit is internally equipped with standard 3300XL eddy current sensing core, and matched with compatible original proximitor transducer and extension cable to constitute a complete non-contact displacement measurement system fully compliant with API 670 industry specification for machinery protection. It is widely deployed on large steam turbines, heavy-duty industrial gas turbines, oversized centrifugal compressors and high-power turbo-generator sets within power generation, petrochemical and metallurgical industries to continuously monitor shaft radial vibration, thrust axial displacement and keyphasor rotational speed signals, and provide over-limit alarm and emergency trip interlock signals to avoid destructive unit shutdown and equipment failure. Each finished probe assembly undergoes strict full-range linearity calibration, high-low temperature cyclic aging test and complete hermetic sealing inspection before factory delivery to maintain consistent and stable measuring accuracy under long-term severe field environments.

The seven-segment part coding follows Bently Nevada standardized naming rule for armored proximity probe products, and each figure stands for exclusive product configuration parameter respectively. The prefix code 21000 represents core heavy-duty armored probe series which features integral metal protective sleeve structure for anti-collision, oil isolation and stress buffering; the second code 16 specifies the housing specification matched for standard 8mm diameter 3300XL internal sensing core with integrated aluminum alloy protective outer shell; the third code 05 indicates the factory pre-molded integral coaxial cable with fixed total length of 5 meters, and the original cable is not allowed to be cut or modified arbitrarily on site to guarantee calibrated electrical performance; the fourth code 15 refers to 1.5-inch exposed sensing tip extension length from the front end of armored sleeve, which is fixed after factory customization for preset installation clearance requirement; the fifth code 060 defines the overall armored sleeve length of 6 inches to satisfy deep hole embedded mounting on thick bearing pedestals; the sixth code 03 means 3/4-14 NPT tapered pipe thread as standard mounting thread for bearing base installation holes; the last suffix code 02 stands for standard rear-end sealing structure and miniature coaxial terminal connector with general industrial sealing configuration without special explosion-proof certification, finished with original factory calibration configuration. Any random replacement or configuration alteration against original part number will break factory matching calibration and result in measurement deviation or unexpected protective channel tripping.

The whole probe assembly consists of internal eddy current sensing core, high-strength stainless steel armored protective sleeve, integral epoxy sealed structure and pre-molded shielded coaxial cable. The armored outer housing and front sensing tip are precision processed from corrosion-resistant stainless steel material with outstanding resistance against lubricant erosion, high-temperature oil vapor and mechanical impact inside closed bearing chambers. The internal induction coil of sensing core is fully potted with high-temperature resistant epoxy resin to eliminate inner air gaps, effectively preventing coil displacement and inter-turn short-circuit faults triggered by long-period equipment vibration and fluctuating ambient temperature. The attached original 5-meter integral coaxial cable adopts standard 75-ohm controlled-impedance coaxial structure with dense tinned copper braided shielding over 95% coverage to restrain external electromagnetic crosstalk during long-distance on-site signal transmission. On-site cutting, joint splicing or arbitrary replacement of original cable and rear-end terminal connector is strictly prohibited, as any physical modification will permanently invalidate factory preset full-set calibration data of the entire transducer system. The integrated armored sleeve design is exclusively optimized for deep embedded installation environment of thick-wall heavy-duty bearing seat structure, which can isolate installation extrusion stress and prevent physical damage during equipment assembly and operation. 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 linear measuring performance of the whole measurement system can only be maintained by genuine original matching of this probe, designated calibrated extension cable and supporting matched proximitor transducer.

The matching original proximitor transducer supplies regulated negative DC working voltage ranging from -17.5 VDC to -26 VDC, and -24 VDC is defined as standard nominal operating voltage for regular industrial field application. Factory fixed calibrated sensitivity is 7.87 volts per millimeter, equal to 200 millivolts per mil, calibrated against standard AISI4140 carbon steel target material, and full-range linearity deviation is strictly controlled within plus or minus five percent complying with API 670 specification requirement. Valid linear measuring range covers 0 mm to 2.54 mm to satisfy routine radial vibration and long-stroke axial clearance detection of large industrial rotating shafts. Effective frequency response range spans from direct current up to 10 kilohertz, synchronously collecting low-frequency static thermal expansion drift signal and high-frequency dynamic shaft vibration signals. The recommended pre-installation gap is positioned near the midpoint of linear measuring range to ensure stable bias working point for long-time uninterrupted equipment continuous operation.

The sensing portion of probe allows continuous operating temperature ranging from minus 35 degrees Celsius to positive 120 degrees Celsius to adapt high-temperature installation surroundings near heated bearing housings and turbine cylinder casings. Storage temperature for spare probe assemblies is controlled between minus 55 degrees Celsius and positive 85 degrees Celsius under dry non-condensing storage environment; applicable working relative humidity ranges from five percent RH to ninety-five percent RH without dew accumulation on probe outer casing and cable outer jacket surface. The probe withstands routine industrial mechanical vibration ranging from 10 hertz to 2 kilohertz generated by adjacent continuously running rotating equipment. Long-term continuous soaking or exposure in corrosive chemical liquid, acid mist and persistent high-temperature steam environment is forbidden to avoid outer casing corrosion and premature aging of internal insulating materials. For installation location above 1000 meters altitude, regular periodic inspection interval shall be appropriately shortened to secure stable service performance.

Cut off total power supply of the whole monitoring loop before field installation, screw the threaded probe body into pre-reserved deep threaded hole of bearing pedestal or custom mounting fixture via standard 3/4-14 NPT thread, adjust pre-set installation clearance to rated design value and lock fastening nut tightly to prevent installation looseness induced by long-term continuous equipment running vibration. During cabling construction, separate probe signal cable routing away from high-current alternating current power cables and inverter output wiring to reduce cross electromagnetic coupling interference. Avoid sharp small-radius bending, excessive stretching and heavy mechanical squeezing on cable body to prevent inner conductor breakage and abnormal impedance shift. Within fixed regular maintenance cycles, periodically inspect cable outer sheath for oil corrosion, abrasion and cracking damage, and check locking tightness of rear-end terminal connector. When replacement is needed after probe failure, only spare part with identical full part number 21000-16-05-15-060-03-02 is permitted for direct swap. 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 loops.