UD049-J53 Proximity Probe Unit

Module Feature

UD049-J53 is factory-calibrated eddy current proximity probe for rotating machinery protection monitoring system.

It adopts integrated sensing coil and sealed ceramic tip structure, anti-oil, anti-steam and high vibration resistant construction, suitable for long-term installation on bearing housing. It detects clearance between probe tip and rotating metal shaft, and outputs raw impedance signal to the paired proximitor conditioner. It must be used together with specified capacitance extension cable and matching proximitor, cannot be replaced arbitrarily. It is stocked as critical maintenance spare for power plant, oil & gas compressor and steam turbine machinery protection rack.

Working principle

High-frequency excitation signal from proximitor is transmitted to the internal coil of probe.

Alternating magnetic field induces eddy current on the surface of rotating shaft. The coil impedance changes with the clearance variation between probe and target shaft. The impedance feedback signal is sent back to proximitor conditioning circuit and converted into linear DC gap voltage, used for vibration waveform calculation, thrust position monitoring, speed keyphasor capture and DCS alarm interlock.

Onboard components

High-frequency sensing coil, ceramic sensing tip, hermetic stainless steel probe body, internal insulated lead wire, thread mounting stud, sealing and strain relief sleeve.

LED indicators

Not applicable. Probe health condition is judged by fault alarm and gap voltage value from matched proximitor module.

Hardware self‑diagnosis

No built-in diagnosis circuit. The supporting proximitor detects probe open circuit, short circuit and abnormal impedance, and uploads fault alarm to monitoring workstation.

Programming software

System 1, used for vibration channel setup, gap voltage verification and fault event recording.

Electrical & Process Parameters

Model:UD049-J53 Brand:OEM turbomachinery monitoring spare Device type:Eddy current proximity probe Function:Non-contact shaft gap detection for radial vibration, axial thrust and keyphasor speed measurement of rotating equipment

Mechanical & Structure

Mounting:Threaded stud installation on probe bracket Protection class:IP66 after proper installation Housing:Stainless steel probe body + ceramic sensing tip

Environmental

Operating temperature:-40℃ ~ +180℃ Storage temperature:-40℃ ~ +85℃ Ambient humidity:5~95% non‑condensing

Certification:API 670 compliant, ATEX optional Status:Original rotating machinery monitoring spare

Installation

Stop rotating equipment before replacement.

Adjust installation gap according to drawing requirement, lock probe lock nut securely, avoid pulling and twisting internal lead, check gap voltage and vibration waveform after commissioning.

Interface

Threaded mounting stud, coaxial interface for matched calibrated extension cable.

Diagnostic

Probe fault alarm: Internal coil break, short circuit or coaxial connector contamination/damage. Vibration signal noisy: Shielding failure, ground loop interference or loose locking nut. Gap voltage drift: Shaft surface scratch, dirt accumulated on ceramic tip or incorrect installation clearance.

Product Brief

UD049-J53 proximity probe, eddy current non-contact sensing spare for turbine and centrifugal compressor vibration monitoring system.