Bently Nevada 21500-00-32-10-02 Eddy Current Proximity Probe Product Specification
21500-00-32-10-02 is factory pre-calibrated front-mounted 14 mm eddy current proximity probe designed exclusively for Bently Nevada 7200 series transducer system. Combined with original 2155/00 proximitor preamplifier and factory-calibrated 75-ohm matched extension cable, the full set constitutes a complete non-contact measurement system complying with API 670 standards for heavy-duty critical rotating machinery protection. Based on eddy-current induction principle, the probe converts tiny clearance fluctuations between sensing tip and conductive metallic rotor target into linear analog voltage signals. These signals are delivered to 7200 or 3500 rack-mounted monitoring modules for continuous online measurement of large-diameter shaft radial vibration, long-stroke axial displacement and Keyphasor rotational pickup pulses. Widely applied on large steam turbines, heavy-duty industrial gas turbines, oversized centrifugal compressors and big turbo-generators in power, petrochemical and metallurgical industries, it outputs over-limit alarm and emergency shutdown interlock signals to safeguard stable unit operation. Every finished probe undergoes full-range linearity calibration, high-low temperature cyclic aging test and complete hermetic epoxy encapsulation inspection prior to factory delivery to maintain consistent measuring accuracy under severe field environments including high bearing housing ambient temperature, persistent lubricant oil mist and complex electromagnetic interference from high-current power cables and variable frequency drive equipment.
Description
Bently Nevada 21500-00-32-10-02 Eddy Current Proximity Probe Product Specification
1. Product Overview
21500-00-32-10-02 is factory pre-calibrated front-mounted 14 mm eddy current proximity probe designed exclusively for Bently Nevada 7200 series transducer system. Combined with original 2155/00 proximitor preamplifier and factory-calibrated 75-ohm matched extension cable, the full set constitutes a complete non-contact measurement system complying with API 670 standards for heavy-duty critical rotating machinery protection. Based on eddy-current induction principle, the probe converts tiny clearance fluctuations between sensing tip and conductive metallic rotor target into linear analog voltage signals. These signals are delivered to 7200 or 3500 rack-mounted monitoring modules for continuous online measurement of large-diameter shaft radial vibration, long-stroke axial displacement and Keyphasor rotational pickup pulses. Widely applied on large steam turbines, heavy-duty industrial gas turbines, oversized centrifugal compressors and big turbo-generators in power, petrochemical and metallurgical industries, it outputs over-limit alarm and emergency shutdown interlock signals to safeguard stable unit operation. Every finished probe undergoes full-range linearity calibration, high-low temperature cyclic aging test and complete hermetic epoxy encapsulation inspection prior to factory delivery to maintain consistent measuring accuracy under severe field environments including high bearing housing ambient temperature, persistent lubricant oil mist and complex electromagnetic interference from high-current power cables and variable frequency drive equipment.
2. Part Number Definition Breakdown
All code segments follow Bently’s standardized part coding specification for 7200-series front-install proximity probes. Base code 21500 represents standard 14 mm diameter full front-thread proximity probe series developed for the 7200 transducer platform; segment 00 stands for zero exposed unthreaded tip length, fixed internal coil construction and factory-locked original calibration parameters without customized electrical modification; segment 32 denotes medium-short full-threaded body dimension suitable for medium-shallow mounting holes on standard heavy-duty bearing pedestals; segment 10 refers to factory pre-molded integral coaxial cable with fixed 1.0-meter length permanently bonded to probe main body during production; final suffix 02 specifies standard miniature male coaxial terminal connector mounted at cable tail for plug-and-play connection with certified original extension cable. Random replacement with differently numbered probes changes mechanical dimensions or calibrated electrical features, invalidates full-loop factory matching calibration and may result in measurement drift or undesired protective tripping of relevant monitoring channel.
3. Core Functional Characteristics
The probe’s threaded housing and sensing tip are precision fabricated from high-strength corrosion-resistant stainless steel with outstanding resistance against lubricant erosion and corrosive vapor trapped inside sealed bearing chambers. Internal induction coil is fully potted with high-temperature resistant epoxy resin to eliminate internal air gaps, effectively preventing coil displacement and inter-turn short-circuit faults triggered by long-term equipment vibration and varying ambient temperature. The attached 1.0-meter integral cable adopts standard 75-ohm controlled-impedance coaxial structure with dense tinned copper braided shielding over 95% coverage to suppress external electromagnetic crosstalk throughout field signal transmission. On-site cutting, splicing or arbitrary replacement of original integral cable and end connector is strictly prohibited; any physical modification permanently voids factory preset calibration data of the entire transducer assembly. Medium-short full-thread front mounting design is optimized for conventional medium-shallow pre-drilled holes and regular medium-thick heavy-duty bearing pedestal structures. Built-in open-circuit and short-circuit fault diagnostics identify abnormal wiring via obvious output voltage deviation to simplify routine field troubleshooting. Stable linear measurement performance of the whole system can only be preserved through genuine original matching of this probe, calibrated extension cable and designated 2155/00 proximitor preamplifier.
4. Electrical and Metrological Specifications
Matching 2155/00 proximitor provides regulated negative DC supply ranging from -17.5 VDC to -26 VDC, with -24 VDC defined as standard nominal operating voltage for industrial field application. Factory-set calibrated sensitivity is 7.87 V/mm (200 mV/mil) referenced against standard AISI4140 carbon steel target material, and full-range linearity deviation is restricted within ±5% per API 670 specification requirements. Valid linear measuring range spans 0 mm to 2.54 mm, satisfying routine radial vibration and long-stroke axial clearance measurement for large industrial rotating shafts. Effective frequency response covers DC up to 10 kHz, enabling synchronous collection of low-frequency static thermal expansion drift and high-frequency dynamic shaft vibration signals. Recommended pre-installation gap is positioned near the midpoint of linear range to maintain a stable bias operating point for prolonged uninterrupted equipment service.
5. Environmental Working Parameters
The sensing portion supports continuous operating temperature from -35°C to +120°C to fit high-temperature installation adjacent to heated bearing housings and turbine casings. Storage temperature for spare units is maintained between -55°C and +85°C under dry non-condensing surroundings; applicable operating relative humidity ranges from 5%RH to 95%RH without dew condensation on probe housing and cable outer jacket. The probe withstands regular industrial mechanical vibration of 10 Hz ~ 2 kHz generated by nearby running rotating equipment. Long-term continuous immersion or exposure to corrosive liquid, acid mist and persistent high-temperature steam is forbidden to avoid outer casing corrosion and premature aging of internal insulating materials. For installation sites above 1000 meters altitude, shorten regular inspection cycle appropriately.
6. Installation and Routine Maintenance Guidance
Disconnect full power of the entire monitoring loop before field installation, screw the medium-short full-threaded probe into pre-reserved medium-shallow threaded holes of bearing pedestals or custom mounting fixtures, adjust pre-set installation clearance to rated design value and fasten lock nut securely to eliminate loosening induced by long-running operational vibration. During cabling work, route the probe signal cable separately away from high-current AC power lines and inverter output wiring to minimize cross electromagnetic coupling interference. Avoid sharp small-radius bending, excessive stretching and heavy mechanical squeezing on cable body to prevent inner conductor fracture and abnormal impedance shift. Within scheduled maintenance cycles, periodically inspect cable outer sheath for oil corrosion, abrasion and cracking, and verify locking tightness of end terminal connector. Upon probe failure requiring replacement, only spare parts with identical full part number 21500-00-32-10-02 are permitted 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.
Get a Quote