Description
PR6423/003-030+CON021 Emerson EPRO Sensor Probe
PR6423/003-030+CON021 is a high-performance eddy current shaft vibration monitoring sensor system manufactured by EPRO (now part of Emerson Baker Hughes), Germany. It is specifically designed for rotating machinery condition monitoring and fault early warning, and is an indispensable core detection component in heavy industries such as power generation, petrochemical, and metallurgy.
[System Composition]
The system consists of two parts: the PR6423/003-030 is an 8mm diameter eddy current probe responsible for non-contact sensing, and the CON021 is a standard proximitor (signal conditioner) responsible for signal amplification and conversion. The two are connected via a LEMO plug, and the system-level calibration is completed at the factory to ensure signal consistency and long-term stability.
PR6423/003-030+CON021 Emerson EPRO Sensor Probe
[Working Principle]
The system operates based on the eddy current effect. The high-frequency coil inside the probe (1–2 MHz) carries an alternating current that generates an alternating magnetic field. When this field approaches the surface of a ferromagnetic shaft, closed-loop eddy currents are induced on the conductor surface. These eddy currents produce a reverse magnetic field that alters the equivalent impedance (inductance and resistance) of the original coil. The impedance change is proportional to the gap distance between the probe and the measured surface. The CON021 proximitor converts this impedance change into a standard DC voltage signal output (typical sensitivity 8 V/mm, i.e. 203.2 mV/mil), thereby enabling precise capture of physical quantities such as shaft vibration and shaft displacement.
[Key Technical Specifications]
Probe diameter: 8mm; static linear range: ±1.0mm; dynamic response: 0–500μm; linearity error: ≤±1% FS; frequency range: 10 Hz–1000 Hz. Sensor operating temperature: -35°C to +200°C; cable temperature rating: up to +200°C. Target material: ferromagnetic steel (e.g. 42CrMo4). Mounting thread: M10×1 or 3/8″-24UNF. CON021 proximitor protection class: IP20; supply voltage: -24V DC; output voltage linear range: -4 to -20V; nominal output: -12V (symmetrical bidirectional measurement range); internal resistance: 100kΩ; response time: only 15μs. Features open-circuit, short-circuit, and reverse polarity protection.
[Application Scenarios]
Widely deployed on critical rotating equipment such as steam turbines, generators, compressors, and ball mills. Capable of performing multiple tasks including shaft vibration monitoring (identifying early faults such as unbalance, misalignment, and bearing wear), axial displacement measurement (preventing thrust bearing overload), speed detection (overspeed protection), differential expansion monitoring (thermal expansion difference control), as well as eccentricity and oil film thickness monitoring. The system integrates seamlessly with mainstream monitoring and protection systems such as EPRO MMS 3000/6000 and Bently Nevada 3500, and complies with international standards including API 670 and DIN 45670.
[Key Advantages]
Non-contact measurement with zero wear and extremely long service life. High sensitivity capable of detecting micron-level vibration changes. Resistant to high temperatures, oil contamination, and electromagnetic interference, enabling long-term stable operation in harsh industrial environments. Easy to install with low maintenance costs. The gap should be set to approximately 1.5mm during installation. Use original low-noise cable and avoid routing parallel to power cables to ensure measurement accuracy.
