MAGNETIC FIELD TRANSDUCERS

The MFT-100 Magnetic Field Transducers is specifically designed to measure the magnetic flux density generated by the rotor poles of salient pole synchronous machines. It is ideally suited for large, low-speed rotating equipment such as hydrogenerators, gearless mill drives, large synchronous motors, and direct-drive wind turbines.

By providing continuous, real-time, and precise measurement of the magnetic field intensity in the air gap, the MFT-100 offers an online solution that enables the early detection of electrical faults — including shorted rotor turns — ensures operational safety, and supports predictive maintenance strategies without requiring machine disassembly.

Key features

Measuring range up to ±2 Tesla
Non-intrusive installation on stator wall without rotor disassembly
Standard 4-20 mA output for easy system integration
Compact and robust design, immune to vibrations and deposits
High accuracy, linearity, and long-term stability
Wide operating temperature range (-25°C to +125°C for sensor)
Interchangeable sensor head for simplified maintenance and replacement

Description

The MFT-100 Magnetic Field Transducer is a compact, high-performance sensor based on Hall-effect technology, specifically designed for accurate magnetic flux monitoring. Its robust construction ensures reliable operation in harsh industrial environments, withstanding temperatures up to 125°C at the sensor head.

The transducer can be powered by a +24V DC standard industrial power supply or directly by MC-monitoring’s data acquisition systems, without requiring additional hardware. Its interchangeable sensor head design facilitates maintenance and minimizes downtime during replacement.

The MFT-100 system consists of a flat magnetic field sensor (MFS-100) and a signal conditioner (MFC-100), providing a standard 4-20 mA output proportional to the measured magnetic flux density (±2 Tesla range). The output can be integrated into MC-monitoring’s condition monitoring software CMS-500P and/or third-party PLC/SCADA systems for real-time analysis and alarms.

Installed on the stator wall, it enables continuous, real-time measurement of the magnetic field in the air gap, offering an online solution that provides essential data on the rotor’s magnetic flux distribution and potential anomalies. This information helps plant operators improve operational reliability, reduce maintenance costs, and prevent unexpected outages in critical rotating machines.

Typical applications include:

Magnetic flux monitoring
Rotor pole condition assessment
Field current unbalance detection
Shorted rotor turn detection
Predictive maintenance and fault root cause analysis

Installation

The MFT-100 sensor head is specifically designed for easy installation:

It is mounted directly on the stator wall, in front of the rotor poles, without the need to disassemble the rotor.
Its small and flat design allows positioning even in narrow air gaps.
A 10m shielded cable connects the sensor head to the external MFC-100 conditioning unit.

Advanced analysis with CMS-500P

The CMS-500P software includes dedicated analysis features designed to process and visualize the magnetic flux data measured by the MFT-100.

Pole Profile View

This view displays the raw magnetic flux waveform over one revolution, showing the magnetic field density measured by the MFT-100 sensor in Tesla. It allows operators to visualize the real-time flux profile generated by each rotor pole.

Pole Signature View

The Pole Signature provides an overview of the absolute flux values per pole, computed from the maximum amplitude of the measured magnetic field density. This view allows operators to easily verify the magnetic flux balance across the rotor and quickly identify poles with significantly lower or higher flux levels.

Pole Polar Plot

The Pole Polar Plot offers a circular visualization of the magnetic flux amplitude distribution around the rotor.
This view simplifies fault diagnosis by clearly highlighting poles that deviate beyond defined thresholds, revealing potential anomalies such as shorted turns.