Bently Nevada 21000-00-00-00-120-03-02 Armored Eddy Current Probe Assembly Product Specification
The 21000-00-00-00-120-03-02 is a factory pre-calibrated heavy-duty armored eddy current proximity probe belonging to Bently Nevada 21000 series integrated armored probe product line. It is purpose-built for deep embedded installation inside heavy-duty bearing pedestals under harsh operating conditions with high ambient temperature, dense lubricating oil mist and complex mechanical assembly stress. This integrated assembly incorporates standard 3300XL proximity sensing core sealed inside an all-metal armored protective sleeve. When paired with factory-certified original proximitor transducer and matched extension cable, it forms a complete non-contact displacement measurement system fully compliant with API 670 international specification for critical rotating machinery protection. Widely adopted on large steam turbines, heavy-duty gas turbines, oversized centrifugal compressors and high-power turbo-generator sets across power, petrochemical and metallurgical industries, the probe conducts continuous online measurement of shaft radial vibration, axial thrust displacement and keyphasor rotational speed, and transmits over-limit alarm and emergency trip interlock signals to prevent catastrophic equipment breakdown caused by abnormal operating status. Every finished probe undergoes full-span linearity calibration, high-low temperature cyclic aging test and comprehensive hermetic sealing inspection prior to factory delivery to sustain stable measuring precision during long-term on-site service.
Description
Bently Nevada 21000-00-00-00-120-03-02 Armored Eddy Current Probe Assembly Product Specification
1. Product Overview
The 21000-00-00-00-120-03-02 is a factory pre-calibrated heavy-duty armored eddy current proximity probe belonging to Bently Nevada 21000 series integrated armored probe product line. It is purpose-built for deep embedded installation inside heavy-duty bearing pedestals under harsh operating conditions with high ambient temperature, dense lubricating oil mist and complex mechanical assembly stress. This integrated assembly incorporates standard 3300XL proximity sensing core sealed inside an all-metal armored protective sleeve. When paired with factory-certified original proximitor transducer and matched extension cable, it forms a complete non-contact displacement measurement system fully compliant with API 670 international specification for critical rotating machinery protection. Widely adopted on large steam turbines, heavy-duty gas turbines, oversized centrifugal compressors and high-power turbo-generator sets across power, petrochemical and metallurgical industries, the probe conducts continuous online measurement of shaft radial vibration, axial thrust displacement and keyphasor rotational speed, and transmits over-limit alarm and emergency trip interlock signals to prevent catastrophic equipment breakdown caused by abnormal operating status. Every finished probe undergoes full-span linearity calibration, high-low temperature cyclic aging test and comprehensive hermetic sealing inspection prior to factory delivery to sustain stable measuring precision during long-term on-site service.
2. Part Number Code Definition
The seven-segment part number follows Bently Nevada’s standardized coding rule for armored proximity probe configuration. The prefix 21000 stands for heavy-duty armored probe series featured with integrated anti-shock and oil-resistant metal outer casing; the second digit 00 denotes the specification matching standard 8 mm diameter 3300XL internal sensing core and corresponding aluminum alloy armored housing; the third code 00 means no factory pre-molded integral cable attached to the probe tail, which requires field connection with genuine matched extension cable complying with original impedance standard; the fourth segment 00 refers to fully recessed sensing tip with zero tip protrusion beyond the front face of armored sleeve to avoid scratch and collision damage during installation and equipment operation; the fifth code 120 defines total armored sleeve length of 12 inches, designed for deep bore mounting on thick-wall heavy-duty bearing housings; the sixth code 03 represents 3/4-14 NPT tapered pipe thread as standard mounting thread for bearing base threaded installation holes; the final suffix 02 indicates standard general industrial rear sealing structure and miniature coaxial male connector without dedicated explosion-proof certification, delivered under original factory calibrated configuration. Arbitrary replacement with mismatched specification probes will invalidate factory preset matching calibration and trigger measurement deviation or unexpected protection channel tripping.
3. Core Construction and Functional Characteristics
The armored sleeve and front protective component are precision fabricated from high-strength corrosion-resistant stainless steel, delivering outstanding resistance against lubricant erosion, high-temperature oil vapor and accidental 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 avoiding coil displacement and inter-turn short-circuit faults induced by long-period equipment vibration and fluctuating ambient temperature. Since no original cable is pre-fixed on probe body, field wiring must adopt certified 75-ohm controlled-impedance extension cable; on-site cutting, splicing or random replacement with non-original cable is strictly forbidden, which would permanently void full-set factory calibration data of the entire transducer system. The fully recessed tip plus medium-long armored sleeve design is optimized for deep embedded installation of thick-wall heavy-duty bearing seats to isolate assembly extrusion stress and protect sensing core from abrasion. Equipped with built-in open-circuit and short-circuit self-diagnosis function, the probe can feed back abnormal wiring condition via obvious output voltage offset to simplify daily field troubleshooting. Consistent linear measurement performance of the whole monitoring system can only be secured by original matching of this probe, designated extension cable and compatible proximitor.
4. Electrical and Metrological Specifications
The matched proximitor accepts regulated negative DC input voltage ranging from -17.5 VDC to -26 VDC, and -24 VDC is specified as nominal standard operating voltage for regular industrial field application. Factory fixed calibration sensitivity is 7.87 V/mm (200 mV/mil) referenced on standard AISI4140 carbon steel target material, and full-range linearity error is controlled within ±5% as required by API 670. Valid linear measuring range covers 0 mm ~ 2.54 mm to satisfy routine radial vibration and long-stroke axial clearance measurement for large-diameter industrial rotating shafts. Effective frequency response ranges from DC up to 10 kHz to synchronously capture low-frequency static thermal expansion drift and high-frequency dynamic shaft vibration signals. The recommended pre-installation gap is arranged near the midpoint of linear range to maintain stable DC bias working point for continuous long-time equipment operation.
5. Environmental Working Parameters
The probe sensing part supports continuous operating temperature from -35°C to +120°C to adapt high-temperature installation environment close to heated bearing housings and turbine casings. Storage temperature for spare probe assemblies is kept between -55°C and +85°C under dry non-condensing storage surroundings; applicable working relative humidity is 5%RH ~ 95%RH without dew condensation on probe outer casing and cable outer jacket. The probe is capable of enduring regular industrial mechanical vibration of 10 Hz ~ 2 kHz generated by adjacent running rotating equipment. Long-term continuous soaking or exposure in corrosive liquid, acid mist and persistent high-temperature steam is prohibited to prevent casing corrosion and premature aging of internal insulating materials. For installation locations above 1000 meters altitude, regular inspection cycle needs to be shortened appropriately.
6. Installation and Routine Maintenance Guidance
Cut off total power supply of the whole monitoring loop before field installation, screw the threaded probe body into pre-processed deep threaded hole of bearing pedestal or customized mounting fixture via standard 3/4-14 NPT thread, adjust installation clearance to rated design value and tighten lock nut firmly to prevent loosening caused by long-running operational vibration. During subsequent cable laying, separate matched extension cable away from high-current AC power cables and inverter output wiring to reduce cross electromagnetic coupling interference. Avoid sharp small-radius bending, excessive stretching and heavy squeezing on cable body to prevent inner conductor breakage and abnormal impedance shift. Within fixed maintenance cycles, periodically inspect probe housing for corrosion and mechanical damage, check extension cable outer sheath for oil corrosion, abrasion and cracking, and confirm fastening tightness of rear coaxial connector. Once probe fails and requires replacement, only spare part with identical part number 21000-00-00-00-120-03-02 is allowed for direct swap. All replacement probes complete full electrical performance testing and alternating temperature aging screening before factory delivery to guarantee full interchangeability inside original vibration monitoring loops.
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