Product Core Brief

• Model: PR6423/003-010
• Brand: EPRO (Emerson Machinery Health Monitoring, Germany)
• Series: standard 8mm eddy current probe series for MMS3000 / A6000 turbo-machinery protection racks
• Model Code Decode: = 8mm sensing head, M10 thread standard eddy current probe/003 = 3 meters factory integrated high-temperature braided coaxial cable-010 = Lemo self-locking circular plug molded cable end (direct mate CON021 front port)
• Core Function: Non-contact eddy current sensor to measure radial shaft vibration, rotor clearance and minor axial displacement on steam/gas turbines, centrifugal compressors and critical rotating equipment safety protection loops, fully API 670 compliant
• Product Type: Complete eddy current probe assembly (M10 probe head + 3m integrated cable + molded Lemo plug)
• Key Specs: M10×1 stainless housing, 8mm sensing tip; ±1mm linear measuring range; factory calibrated 8V/mm sensitivity matched for CON021; high-temperature PTFE braided cable, pre-molded Lemo locking connectorNote: Discontinued legacy machinery monitoring hardware, stocked as unopened factory calibrated new surplus; must pair with CON021 single-channel rack preamplifier for usable linear gap voltage output.

 

Key Technical Specifications

/003-010 Probe Assembly

1. Mechanical Structure

• Thread: M10 × 1.5 stainless steel housing, standard body length
• Sensing head diameter: 8mm
• Integrated cable length: 3m continuous high-temperature braided coaxial cable
• Cable termination suffix -010: Molded Lemo self-locking plug (direct plug into CON021 front port, no bare wire terminals)
• Minimum cable bend radius: ≥50mm, sharp bends will damage internal coaxial core and cause signal drift
• IP rating: Probe head IP67; braided cable IP65 for cabinet routing

1. Measurement Performance

• Full linear measuring span: ±1mm (total 2mm measuring range)
• Recommended installation nominal midpoint air gap: 1.0 mm
• Calibrated sensitivity (matched CON021): 8 V/mm
• Maximum linearity error: ≤ ±1% full measurement span
• Frequency response: DC ~ 20kHz (-3dB), covers full turbine low/high frequency vibration spectrum
• Thermal drift index: Zero point drift 200mV / 100K; sensitivity drift ≤2% full scale per 100K
• Long-term zero drift: ≤0.3% FS over 12 months continuous operation

1. Thermal & Environmental Limits

• Probe head continuous operating temperature: -35°C ~ +180°C; transient peak +200°C
• Braided cable temperature rating: Max 200°C
• Storage & transport temperature: -40°C ~ +70°C
• Vibration resistance: 5g continuous vibration at 60Hz bearing housing mounting
• Working ambient pressure: Uniform 2bar external environment
• Minimum target rotor diameter: 25mm carbon steel shaft; stainless steel/aluminum coated shafts require on-site recalibration

Matching Preamplifier Reference Spec

• Power input: 10–30 VDC rack supply (standard 24VDC MMS3000 chassis)
• Probe excitation: -26.75 VDC short-circuit protected sensor power supply
• Analog output: Linear 0~16VDC voltage proportional to shaft gap; requires load impedance ≥10kΩ for DCS/monitor cards
• Galvanic isolation between field probe circuit and rack backplane bus
• Cabinet operating temperature: -20°C ~ +60°C
• Form factor: Single-slot 3U DIN41612 rack plug-in module
• PCB protection: Full acrylic conformal coating for refinery/offshore corrosive cabinet atmospheres

Combined Mechanical Data

• Probe assembly net weight: ~0.18kg
• module dimensions: 128mm H × 25mm W × 160mm D; weight ~0.38kg

 

Product Introduction

This 3-meter cable M10 eddy current probe is the mainstream standard sensor for power plant and petrochemical turbo-machinery vibration protection systems complying with API 670 standards. Adopting non-contact eddy current induction measurement principle, there is no mechanical friction and wear between the probe tip and rotating metal rotor, which can realize long-term stable radial vibration and rotor clearance monitoring for large rotating equipment.The 3-meter factory integrated braided cable adapts to medium-distance wiring layouts between bearing housings and marshalling cabinets; the molded Lemo plug (-010 suffix) realizes plug-and-play docking with preamplifier, eliminating on-site cable terminal wiring work and reducing maintenance error risks.When factory calibrated and matched with dedicated signal conditioner, it converts tiny coil inductance changes into standard linear 8V/mm analog signals, which can be directly transmitted to MMS3000 monitoring racks, PLC and DCS safety trip logic for vibration protection interlock judgment.Typical application scenarios: steam turbines, gas turbines, centrifugal compressors, large blowers and other critical rotating machinery radial vibration monitoring points.

 

QA & Testing SOP (Transparency Building)

1. Incoming Inspection: Cross-reference serial calibration numbers printed on probe and factory calibration certificate; inspect probe tip for scratches, braided cable abrasion, cracked molded Lemo plug shell and internal pin deformation; verify original anti-static packaging and calibration certificate seal integrity.
2. Live Bench Calibration Test: Mount probe on precision micrometer test jig, powered by Fluke stabilized 24VDC supply paired with matched ; run 24-hour continuous full ±1mm gap sweep test, record linearity error, zero thermal drift and 8V/mm sensitivity output under 25°C and 60°C simulated cabinet temperature.
3. Electrical Insulation Test: Megger insulation resistance >10MΩ between cable shield and rack ground; perform vibration cycle test to confirm molded Lemo connector maintains stable signal without intermittent dropout.
4. Calibration Record Backup: Archive original factory calibration certificate recording nominal air gap, sensitivity and linearity tolerance; document rear terminal wiring polarity for field maintenance reference.
5. Final QC Packaging: Attach serialized printed test pass tag with linearity test data; coil the 3m braided cable with foam separators to prevent braided wire abrasion; seal the probe in foam-lined static-shielded bag to protect the sensing tip and Lemo connector during storage and transit.

 

Installation Pitfalls & 4-Step Replacement Guide

❗ Calibration Matching Risk: The probe must be used with factory-matched preamplifier as a complete set. Cross-matching with unmatched preamplifiers will cause severe linearity deviation, leading to invalid turbine vibration safety trip thresholds.❗ Air Gap Misadjustment Risk: Standard midpoint installation gap = 1.0mm. Working outside the 0.2mm ~ 1.8mm linear window will clip analog output signals and create blind vibration fault conditions for safety protection systems.❗ EMI Interference Risk: Route the 3m probe cable completely separated from high-current VFD and motor power cables; parallel power wiring induces electromagnetic noise and triggers false vibration alarms on DCS monitoring screens.❗ Target Material Deviation Risk: Factory calibration is only valid for standard carbon steel rotors. Stainless steel, aluminum or coated shaft surfaces change measurement sensitivity and require full on-site recalibration.❗ ESD Circuit Damage Risk: Ungrounded technicians touching Lemo connector pins will damage the internal oscillator circuit inside ; latent ESD damage causes slow zero drift that appears after 2–4 weeks of continuous turbine operation.

4-step replacement guide:

1. Pre-install LOTO: Lock out rotating machinery and MMS3000 rack 24VDC power; attach grounded anti-static wrist strap to cabinet DIN rail ground bar; take photos to record the original probe mounting thread depth and Lemo connector orientation for reference.
2. Removal: Unscrew the old probe from the bearing housing mount; carefully uncoil the 3m cable while maintaining ≥50mm bend radius; unlock the molded Lemo plug from the legacy ; label all rack power and signal terminal wiring.
3. Hardware Install: Thread the new /003-010 probe into the bearing mount; adjust the lock nut to set a 1.0mm nominal air gap with a precision feeler gauge; route the 3m braided cable away from power wiring; fully lock the molded Lemo plug into the front port of the new ; insert the preamplifier into an empty MMS rack slot and re-terminate rack wiring according to original polarity.
4. Power-on Validation: Restore rack power; use the micrometer gap jig to verify linear 8V/mm output across the full ±1mm travel range; access MMS/DCS monitoring screens to confirm stable zero offset, no noise spikes and valid radial vibration readings without false safety alarms.

 

FAQ

Q: Can /003-010 measure both radial vibration and axial thrust displacement?A: It can only measure small-range axial clearance within the ±1mm span. Long-range axial thrust monitoring requires the PR6424 M18 series probe with ±2mm full linear range; separate dedicated probes are recommended for simultaneous radial + thrust monitoring on turbine bearing housings.Q: Does the preamplifier support hot-swapping while the MMS3000 rack remains energized?A: The rack module supports hot extraction from the live slot, but the Lemo probe connector must be fully disconnected first. Live unplugging of the probe cable generates transient voltage spikes that damage the front-end oscillator circuit.Q: What warranty coverage applies to bench-tested calibrated /003-010 probes?A: All stocked calibrated probes carry a 12-month functional warranty covering factory calibration linearity, cable integrity, molded Lemo connector and internal sensing coil circuit defects. Damage caused by improper air gap adjustment, unshielded EMI wiring, reversed power polarity or ungrounded ESD handling is excluded from warranty coverage.Q: Is there a direct drop-in modern replacement for this discontinued series probe?A: Emerson’s current EZ1080 M10 eddy current probe provides equivalent measurement performance, but the Lemo mechanical interface, rack pinout and 8V/mm sensitivity scaling are inconsistent. Full cabinet wiring re-termination and DCS vibration trip threshold revalidation are required with no unmodified direct swap solution.Q: Can multiple probes share a single preamplifier?A: Not supported. is a single-channel dedicated signal conditioner designed for one calibrated probe only. Additional vibration measurement points require independent full matched probe + kits for each channel.Q: What is the difference between suffix -010 and -000 on probes?A: -010 = factory molded Lemo plug integrated at cable end, direct plug into without field wiring; -000 = bare open cable wire ends, need manual terminal wiring to CON031/CON041 preamplifiers.