115788-516 Proximity Probe Unit

Module Feature

115788-516 is factory calibrated eddy current proximity probe for turbomachinery protection monitoring system.

It adopts hermetically sealed metal housing and ceramic sensing tip, oil and steam resistant design, suitable for long-term installation on bearing housing. It detects clearance distance between probe tip and metal rotor surface and transmits raw impedance signal to matched proximitor conditioner. It must be used together with designated calibrated extension cable and compatible signal conditioner, random cable replacement will cause measurement deviation. It is stocked as critical maintenance spare for power plant, refinery and compressor safety monitoring rack.

Working principle

High-frequency excitation signal from proximitor module is delivered to internal sensing coil.

Alternating magnetic field induces eddy current on the surface of rotating metal shaft. Coil impedance changes linearly with the gap between probe and target. The proximitor converts impedance variation into standard gap voltage signal, which is used for vibration waveform collection, thrust position monitoring and speed keyphasor capture. Built-in channel diagnosis on proximitor detects open circuit, short circuit and abnormal impedance, and triggers system alarm.

Onboard components

Internal sensing coil, ceramic tip, stainless steel probe body, insulated internal lead, threaded mounting stud, sealing fitting and strain relief boot.

LED indicators

No local LED indicator. Operating status and fault alarm are displayed on matched proximitor monitoring module.

Hardware self‑diagnosis

Diagnosis is completed by matched proximitor, detects probe open circuit, short circuit and signal out of range. Channel verification and fault checking use dedicated turbomachinery monitoring configuration software.

Programming software

System dedicated instrument commissioning tool, used for gap voltage verification, channel parameter setup and fault log reading.

Electrical & Process Parameters

Model:115788-516 Brand:OEM Device type:Eddy current proximity probe Function:Non-contact clearance measurement for radial vibration, axial thrust and keyphasor speed signal acquisition of rotating machinery

Mechanical & Structure

Mounting:Threaded stud installation on probe bracket Protection class:IP66 after proper installation Housing:Stainless steel sealed probe housing with ceramic tip

Environmental

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

Certification:API670 compliant, ATEX optional Status:Original turbomachinery monitoring spare

Installation

Stop rotating equipment and power off monitoring rack before replacement.

Adjust installation gap according to drawing requirement, tighten lock nut securely, avoid sharp bending and pulling of internal lead, test gap voltage and vibration waveform after commissioning.

Interface

Threaded mounting stud, coaxial connector for matched extension cable.

Diagnostic

Probe fault alarm: Internal coil open/short, connector contamination or wire damage. Unstable vibration signal: Shield grounding error, ground loop interference or loose nut. Gap reading deviation: Mismatched extension cable, wrong total system capacitance.

Product Brief

115788-516 proximity probe, eddy current non-contact vibration sensor spare for turbine and centrifugal compressor machinery protection monitoring system replacement.