GE MMS3-221-40-0400 is a standard original proximity sensor under the GE MMS sensor family, perfectly compatible with the 3500 series online vibration monitoring system widely used in thermal power and petrochemical industries. The whole set consists of a sensing probe head, fixed threaded shell and matched shielded extension cable, adopting the eddy current sensing principle to achieve non-contact real-time measurement of rotor radial vibration, axial thrust displacement and shaft offset of steam turbines, generators, large fans and centrifugal compressors.

The probe core is wound with high-precision enameled coil components with excellent temperature stability. The outer metal housing adopts high temperature and oil mist resistant alloy material, with integral sealed packaging structure, effectively isolating the erosion of high temperature steam, lubricating oil fog, dust and humid gas in the bearing box working environment. It will not produce friction wear with the high-speed rotating shaft surface during long-term operation, so the measurement accuracy will not decline with the extension of service time.

The product is calibrated strictly according to standard displacement values before leaving the factory to ensure excellent linear output within the rated measuring range. The supporting double-layer shielded cable can weaken electromagnetic interference from high-voltage equipment, frequency converters and power distribution cabinets in the site environment, preventing signal distortion and abnormal false alarms of the monitoring system. The standard external thread structure facilitates fixed installation on bearing seats, and staff can finish gap debugging between the probe and the measured shaft surface quickly with standard calibration tools.

Weak displacement signals captured by the probe are transmitted to the front-end conditioning module and then uploaded to the rack monitoring card for data calculation, waveform analysis and threshold judgment. Once the unit has faults such as rotor unbalance, bearing fatigue wear, shaft misalignment and abnormal thrust bearing displacement, the sensor can feed back abnormal data in real time to trigger sound-light alarm or system interlock protection, avoiding severe mechanical damage and unplanned shutdown accidents of the unit.

Internal electronic parts are treated with conformal coating to resist damp and corrosive gas inside the control cabinet. Each finished product passes vibration aging, high and low temperature cycle test and long-term power-on stability test to meet the requirement of 24-hour uninterrupted online monitoring all year round. As a common maintenance spare part for power station monitoring loops, standardized plug wiring simplifies field replacement work, shortens equipment maintenance downtime and reduces the operation risk of the unit during maintenance. It is massively applied in thermal power units, gas turbine equipment, petrochemical process compressors and other key rotary equipment state monitoring and predictive maintenance systems.