Rapid measuring device and measuring method for permanent magnet failure temperature

A rapid measuring device for permanent magnet failure temperature, comprising:

• a measurement system (1) configured with a computer and a connector, wherein the computer is connected to an infrared thermal imager (2), a vacuum Hall probe (3) and a laser heating device (4) through the connector;
• the infrared thermal imager (2) configured to:
• monitor and record temperature changes of a permanent magnet sample (5) in real time, and transmit the recorded temperature changes to the computer;
• the vacuum Hall probe (3) configured to:
• measure magnetic field changes of the permanent magnet sample (5) during heating, and transmit the measured magnetic field changes to the computer;
• and
• the laser heating device (4) configured to control laser output energy for heating the permanent magnet sample (5);
• wherein the computer is configured to:
• obtain a change curve of magnetic field and temperature of the permanent magnet sample (5) by analyzing the recorded temperature changes from the infrared thermal imager (2) and the measured magnetic field changes from the vacuum Hall probe (3);
• calculate a first derivative with the change curve of magnetic field and temperature to obtain a curve of first derivative and temperature;
• and
• determine a failure temperature of the permanent magnet sample (5) based on the curve of first derivative and temperature, wherein the failure temperature is a temperature corresponding to a starting point of maximum trough of the curve of first derivative and temperature.