Emerson PR6423/003-110 CON021 Eddy Current Sensor

Emerson PR6423/003-110 (often referenced with the CON021 connector variant) is a high-performance eddy current displacement sensor designed for non-contact measurement of shaft vibration, axial position, and eccentricity in critical rotating machinery . As part of the renowned EPRO series of sensors, this probe is engineered to meet the stringent demands of the API 670 standard, delivering reliable, accurate data to machinery protection systems like the CSI 6500 and AMS 6500 platforms .

What is the Emerson PR6423/003-110?

The PR6423/003-110 is a non-contact eddy current sensor that measures the relative motion between a rotating shaft and the machine casing . Unlike piezoelectric sensors that measure casing vibration, this probe focuses directly on the dynamic behavior of the rotor itself. It operates on the principle of eddy currents: a high-frequency signal is generated by a driver (such as the CON021 converter) and sent to the probe tip. As the shaft moves, the gap changes, modulating the signal and producing an output voltage directly proportional to the displacement .

The "/003" designation typically indicates the probe's specific design characteristics or sensitivity range, while the "/110" often relates to the cable length or connector configuration—in this case, designed to interface seamlessly with the CON021 signal converter .

Key Technical Specifications (Specs)

The Emerson PR6423/003-110 is built for the rigors of continuous industrial operation.

Manufacturer: Emerson (EPRO)

Product Type: Eddy Current Displacement / Vibration Sensor

Model Number: PR6423/003-110

Connector Configuration: CON021 compatible

Measurement Principle: Eddy current (non-contact)

Typical Applications: Shaft relative vibration, radial/axial position, eccentricity, keyphasor

Output Frequency: 50 kHz

Power Requirement: Typically powered via signal converter (e.g., CON021) at 220V input rating

Weight: 0.3 kg (lightweight for ease of installation)

Certification: Industry-certified for safety and performance

Compliance: Designed to meet API 670 standards for machinery protection

The Critical Role of Eddy Current Sensing

For large rotating machinery such as steam turbines, gas turbines, and centrifugal compressors, the health of the rotor is paramount. The PR6423/003-110 provides the eyes into the machine that operators and protection systems rely on. By measuring the actual dynamic motion of the shaft within the bearing clearances, it detects issues invisible to casing-mounted sensors:

Shaft Vibration: Measures the dynamic motion (displacement) of the rotor relative to the bearing housing.

Axial Position (Thrust): Monitors the axial movement of the rotor to detect thrust bearing wear.

Eccentricity: Measures the slow-speed bow or bend in the shaft during startup.

Speed Measurement: When used with a keyphasor notch, provides precise rotational speed and phase reference.