PR6426/010-000 CON021 Emerson Epro Eddy Current Measurement System

Product Overview

The PR6426/010-000 CON021 (PR6426/010-000 CON021) is a specialized non-contact eddy current measurement system designed for the most demanding turbomachinery protection applications. This high-reliability set combines a 12 mm displacement sensor with a Lemo-plug compatible signal converter to monitor shaft vibration, axial position, and eccentricity in power plant turbines, high-speed compressors, and industrial fans. By providing continuous, micron-level data to systems like the AMS 6500, this system acts as a critical early-warning mechanism. Its ability to operate in extreme environments—including high-pressure oil and temperatures up to 175 deg C—ensures operational safety and prevents catastrophic mechanical failures that lead to expensive unplanned outages.

Technical Configuration (Deep Dive)

The system utilizes a matched-impedance inductive circuit to translate physical displacement into a standardized analog voltage.

• Sensor Head (PR6426): Features a 12 mm diameter ceramic tip. The larger tip diameter relative to standard 8 mm sensors allows for a significantly wider magnetic field and a more robust linear measuring range, making it ideal for large-scale industrial shafts.

• Signal Converter (CON021): Acts as the high-frequency driver and signal conditioner. It is specifically designed for the PR642x series and utilizes a self-locking Lemo-plug for the transducer connection, ensuring a vibration-proof electrical link.

• Linearity & Accuracy: The system is engineered to maintain a linearity error of less than or equal to 1.5 percent over its standard measuring range, providing the deterministic performance required for safety-instrumented systems (SIS).

• Dynamic Performance: With a frequency range of 0 to 20,000 Hz and a rise time of less than 15 microseconds, the CON021 captures high-frequency vibration transients that are often missed by lower-specification converters.

Technical Specifications

Technical FAQs

Q1: What is the benefit of the Lemo-plug connection on the CON021?

A1: The Lemo-plug is a self-locking connector that prevents accidental disconnection due to high machine vibration. It also ensures a consistent impedance at the connection point, which is vital for the accuracy of eddy current measurements.

Q2: Can the PR6426/010-000 be used in submerged oil applications?

A2: Yes, the sensor tip is hermetically sealed and pressure-resistant up to 10 bar at the sensing face, making it suitable for installation inside gearboxes or hydrodynamic bearings where oil mist or submersion is common.

Q3: How do I choose between the -2 V to -18 V and -4 V to -20 V output ranges?

A3: This is determined by your host system's input card requirements. The CON021 supports both, but you must ensure the supply voltage is matched (e.g., -21 V to -32 V for the -2 V to -18 V output range).

Engineering & Installation Guide

• Gap Voltage Setup: For precise measurement, the sensor must be gapped to the "Zero" point of the linear curve, typically resulting in a -10 VDC output at the CON021. Use a micrometer fixture during installation to verify the gap before tightening the mounting nuts.

• Cable Integrity: The sensor cable is an integral part of the measurement circuit. Do not cut, splice, or shorten the cable, as this will alter the system inductance and invalidate the factory calibration.

• Mounting Side-Clearance: Ensure a minimum clearance of 1.5 times the tip diameter (approx. 18 mm) from any metallic side-walls to prevent "side-loading" effects that distort the magnetic flux and lead to false readings.

Engineering Advantages

The PR6426/010-000 CON021 set stands out for its superior thermal stability and "fit-and-forget" reliability. The 12 mm tip diameter allows for a larger physical clearance between the sensor and the target, reducing the risk of mechanical contact during extreme shaft surge. Furthermore, the CON021's aluminum housing (LMgSi 0.5 F22) provides excellent RFI/EMI shielding, ensuring that the critical vibration signals remain pure even when the system is mounted in close proximity to high-voltage generators or frequency drives.