Description
The Bently Nevada 21000-28-05-00-060-03-02 is an 8mm eddy-current proximity probe featuring a 3/8-24 UNF threaded body. As a core component of the legacy 7200 series machine protection family, this sensor tracks static and dynamic distances between its tip and a rotating target shaft. It provides high-speed, non-contact measurements of radial vibration, axial thrust position, and speed on critical industrial assets like turbo-compressors, pumps, and gearboxes.
Option Code Breakdown
- 21000: 3/8-24 UNF Thread, 8mm Tip Diameter Proximity Probe (7200 Series)
- 28: Unthreaded Length Option (2.8 inches)
- 05: Overall Case Length Option (0.5 inches)
- 00: Connector Option (Standard miniature coaxial connector, male click-lock style)
- 060: Total Length Option (6.0 meters / approximately 19.6 feet total calibrated system length)
- 03: Fluid Seal / Armor Option (Includes flexible stainless steel armor conduit)
- 02: Agency Approval Option (Multi-agency international hazardous area certifications, ATEX/IECEx compliant)
Commercial Supply Status
- Condition: New Original (Factory Sealed)
- Availability: In stock
- Lead Time: Ships within 1–2 business days
- Warranty: 12-month industrial replacement warranty
- Price Policy: Because legacy 7200 series hardware is subject to limited factory allocation pools and material updates, our listed pricing is a reference baseline. Final transaction pricing is open to negotiation depending on volume requirements. Contact our sales desk to request a firm commercial quote.
Technical Parameters
| Parameter | Value |
| Probe Tip Diameter | 8.0 mm (0.315 in) |
| Thread Profile | 3/8-24 UNF-2A |
| Linear Measurement Range | 2.0 mm (80 mils) nominal |
| Scale Factor | 7.87 V/mm (200 mV/mil) when integrated with matching driver |
| Calibration Standard | AISI 4140 carbon steel target |
| System Length Configuration | 6.0 meters (probe + integrated extension cable) |
| Protective Sleeve | 5.8 mm (0.23 in) outer diameter stainless steel armor braid |
| Operating Temperature | −35 to +177°C |
Field Deployment Notes & Insights
During a mid-frame overhaul on a centrifugal gas compressor, we installed several of these 6.0-meter configurations for radial vibration tracking. Well, technically the 0.5-inch threaded case length gives you a compact profile, but paired with the 2.8-inch unthreaded sleeve, it means the probe must slide deeply into a specialized internal bracket sleeve. Don’t underestimate the potential for oil sludge inside the sleeve to bind the probe head during insertion.
When establishing the physical air gap between the probe tip and the target shaft, use a calibrated digital voltmeter to verify the DC bias voltage rather than relying solely on feeler gauges. This design choice is actually clever because aiming for a raw −10.0 V DC baseline puts the probe exactly in the center of its 80-mil linear range. Wrap the click-lock coaxial connector at the driver junction with clear, self-fusing silicone tape—though your mileage may vary if you leave the bare metal connector exposed to accumulate conductive moisture inside the junction box. Is the shaft surface free of magnetic chrome plating? Verify with the official OEM mechanical installation layout before final loop verification. Bottom line—electrical runout from improper shaft finishing will ruin your vibration trends.
International Shipping & Trade Compliance
Cross-border freight logistics for specialized proximity monitoring loops require strict legal documentation. We declare this device globally under HS Code 90319000. Our trade compliance team prepares all requisite commercial invoices to guarantee clean passage through major logistics gateways via premium air couriers (DHL, FedEx).
Because this product features the “02” multi-agency explosion-proof suffix, the localized compliance certificates are verified against the physical serial engraving plates at our outbound warehouse. Standard international shipments operate under FCA (Free Carrier) or CIP (Carriage and Insurance Paid to) trade rules.
Frequently Asked Questions
Can I use a 5-meter extension cable with this 6.0-meter probe?
No. This probe is explicitly calibrated for a 6.0-meter total system length configuration. Mixing mismatching physical cable lengths with standard Proximitor drivers alters the internal impedance, throwing off the 200 mV/mil scale factor completely.
What is the purpose of the flexible stainless steel armor option?
The stainless steel armor braid prevents mechanical cutting, crushing, and hot oil abrasion from damaging the internal coaxial cable inside high-vibration turbine hoods.
