Emerson PR6423 Series Eddy Current Sensor 8mm Non-Contact

Emerson PR6423 Series (formerly EPRO PR6423) is a precision-engineered 8mm eddy current sensor designed for non-contact measurement of critical rotating machinery parameters. As part of Emerson's comprehensive machinery protection portfolio, this sensor represents the gold standard for monitoring shaft vibration, displacement, position, eccentricity, and speed in high-value turbomachinery applications.

Core Technical Specifications

The PR6423 series delivers exceptional performance metrics that meet or exceed API 670 requirements for machinery protection systems .

Parameter Specification

Probe Tip Diameter 8 mm

Linear Measurement Range 2 mm (80 mils) total 

Static Range ±1.0 mm (±0.040") 

Dynamic Range 0 to 500 μm (0 to 0.020") 

Sensitivity 8 V/mm (203.2 mV/mil) ±5% @ 0-45°C 

Incremental Scale Factor (ISF) 8 V/mm ±5% 

Deviation from Best Fit Line (DSL) ±0.025 mm (±1 mil) @ 0-45°C 

Initial Air Gap (Nominal) 0.5 mm (20 mils) 

Center of Measuring Range 1.5 mm (0.06") nominal 

Minimum Shaft Diameter ≥25 mm (0.98") for optimal performance 

Target Material Ferromagnetic steel (42CrMo4 / AISI 4140 standard) 

Maximum Surface Speed 2500 m/s (98,425 ips) 

Frequency Response Up to 10 kHz 

Operating Temperature -35°C to +180°C (-31°F to +356°F) standard; extended versions available 

Maximum Cable Temperature 200°C (392°F) 

Temperature Error <2%/100°K (API compliant) 

Pressure Resistance 10,000 hPa (145 psi) at sensor head 

Protection Class IP66 (IEC 60529) 

Material Stainless steel sleeve, PTFE cable insulation 

Weight ~100-200 grams (sensor with 1m cable, no armor) 

Compliance API 670, DIN 45670, ISO 10817-1, CE, ATEX, CSA, IECEx 

Understanding the PR6423 Model Numbering System

The Emerson PR6423 uses a sophisticated ordering matrix that defines the exact configuration of each sensor . The model number follows this structure:

PR6423 / X X X X X X

Standard Cable Length Variants

Model Number Cable Length Thread Type Armor Termination Key Features

PR6423/000-000 4m M10x1 With armor LEMO Base model, standard configuration 

PR6423/000-030 8m M10x1 With armor LEMO Extended cable length 

PR6423/000-031 8m M10x1 With armor Open end Field-terminable option 

PR6423/000-040 10m M10x1 With armor LEMO 40m cable for remote mounting 

PR6423/000-120 20m M10x1 With armor LEMO Long-distance installation 

PR6423/000-131 8m M10x1 With armor LEMO Special configuration 

PR6423/002-000 4m 3/8-24UNF With armor LEMO UNF thread option 

PR6423/002-030 8m 3/8-24UNF With armor LEMO UNF thread, extended cable 

PR6423/002-031 8m 3/8-24UNF With armor Open end UNF thread, open termination 

PR6423/003-030 8m Custom With armor LEMO Special thread configuration 

PR6423/003-031 8m Custom With armor LEMO With CON041 converter 

PR6423/003-110 4m Custom With armor LEMO 4m cable, special config 

PR6423/004-030 8m Special With armor LEMO Extended range variant 

PR6423/009-010 5m Special With armor LEMO Signal converter configuration 

PR6423/010-010 5m M10x1 Without armor LEMO Non-armored cable 

PR6423/010-030 8m M10x1 Without armor LEMO Non-armored, extended length 

PR6423/010-040 10m M10x1 Without armor LEMO Non-armored, 10m cable 

PR6423/011-130 8m Special With armor LEMO Industrial grade 

PR6423/013-030 8m Special With armor LEMO Digital output module variant 

PR6423/014-010 5m Special With armor LEMO High-frequency, low-noise performance 

PR6423/014-110 4m Special With armor LEMO 4m cable variant 

"10R" Series (Reverse Thread / Special Configurations)

Model Number Cable Length Thread Type Termination Key Features

PR6423/10R-010 5m Reverse thread CON021 Popular for retrofit applications 

PR6423/10R-030 8m Reverse thread CON021 Extended cable, commonly stocked 

PR6423/10R-040 10m Reverse thread CON021 10m cable with CON021 

PR6423/10R-111 Special Reverse thread CON041 Special configuration 

PR6423/10R-131 8m Reverse thread CON031 With CON031 converter 

Chinese Market Variants (-CN Suffix)

Model Number Configuration Converter Key Features

PR6423/000-030-CN Standard 8m CON021 Chinese market version 

PR6423/000-031-CN Standard 8m, open CON021 With CON021 converter 

PR6423/002-040-CN UNF thread, 10m CON041 UNF thread option 

PR6423/003-030-CN Custom thread, 8m CON021 With CON021 

PR6423/009-010-CN Special, 5m CON021 Signal converter variant 

PR6423/010-040-CN Non-armored, 10m CON021 Non-armored option 

PR6423/011-131-CN Special CON031 With CON031 converter 

PR6423/00R-111-CN Custom armor CON041 Special Chinese variant 

Signal Converters: CON011, CON021, CON031, CON041

The PR6423 sensor requires a signal converter (demodulator) to function as a complete measurement system. The converter provides power, processes the RF signal, and outputs a standardized voltage proportional to the gap .

Converter Model Connector Type Key Features

CON011 LEMO (straight) Standard configuration, screw terminals 

CON021 LEMO (angled) Most common, wide compatibility, -24V supply 

CON031 LEMO (military style) Heavy-duty, high-reliability applications 

CON041 Screw terminal Direct wiring, no LEMO connector 

Converter specifications :

Frequency range (-3dB): 0-20,000 Hz

Rise time: <15 μs

Supply voltage: -23V to -32V (for -4V to -20V output); -21V to -32V (for -2V to -18V output)

Protection class: IP20

System Integration

The PR6423 sensor series integrates seamlessly with Emerson's comprehensive machinery protection platforms :

AMS 6500 Machinery Health Monitor

VM600 Series Monitoring Systems

MMS 6000 Series Monitors (MMS6110, MMS6210, MMS6312, etc.) 

CSI 6500 Machinery Protection System (A6110, A6210, A6220 monitors) 

The Emerson PR6423 Series 8mm Eddy Current Sensor represents the pinnacle of precision measurement technology for critical turbomachinery protection. With its robust construction, exceptional accuracy, and comprehensive model selection, it provides engineers and reliability professionals with the confidence that their most valuable rotating assets are continuously monitored and protected.

Whether you require standard configurations like the PR6423/000-030 or specialized variants such as the PR6423/10R-131 CON031, the PR6423 series offers a solution for every turbomachinery monitoring application. Backed by Emerson's global support network and compliant with API 670 standards, these sensors deliver the reliability and performance that modern industry demands.