Qt-800 automatic fast tester for permanent magnet characteristics is manufactured with original technology. It is the crystallization of modern magnetic measurement technology and the latest electronic technology. Qt-800 has stable performance, fully automatic operation, digital display and audible and visual alarm for unqualified products. A variety of measurement modes can be selected. It can be used for the measurement and inspection of various magnets such as Nd-Fe-B, ferrite and samarium cobalt. It is widely used in manufacturers, users and sales units of NdFeB, ferrite, samarium cobalt and other magnets.

    Qt-800 is a precision measuring instrument, which should be placed on a dry and stable plane to avoid excessive dust and strong current interference. During installation, connect the front of the host to the test bench with a signal cable. Each host and test bench are jointly debugged and calibrated in the factory. Therefore, if there are multiple sets of qt-800 testers, please pay attention to the corresponding installation of each host and each test bench during installation. The product serial number is at the bottom of the host and test bench, which can be used as the basis for corresponding connection.

    The testing idea of this set of instruments is the comparison method. That is: use this equipment to measure a qualified standard sample and get a value, which is the standard value. Then, the permanent magnet products can be measured quickly and continuously, and the measurement results can be compared with the standard value: if it is greater than the standard value, the sample to be tested is qualified; if it is lower than the standard value, the sample to be tested is unqualified.

    Qt-800 tester adopts the open circuit measurement method to measure the magnetic flux of the lower plane of the permanent magnet. Because the open circuit measurement will produce magnetic leakage, the indication of the instrument is not the absolute magnetic flux, but the direct correlation of the magnetic flux. For permanent magnet products of the same specification, the shape and demagnetization factor of the sample are the same, so the magnetic flux leakage ratio is the same in the case of open circuit measurement. The relative magnetic flux of different permanent magnets of the same specification can be compared. The user can set the standard value (i.e. alarm threshold) in the instrument. When the measured value of permanent magnet products is lower than the standard value, the instrument will generate audible and visual alarm.

    Determination of standards

    1) Draw the known limit standard sample across the qt-800 test bench to obtain an instrument indication, and then multiply the indication by the percentage to be controlled to obtain the required limit range.

    2) The instrument inspection standard is obtained by comparing the measurement results of the past testing equipment with the measurement results of qt-800.

• Blank detection of permanent magnet

When qt-800 detects the blank, if the surface of the newly sintered magnet is too rough, the magnet surface can be slightly polished before measurement, which can improve the measurement accuracy.

• Inspection of finished products before electroplating

If Nd-Fe-B is detected after on-line cutting and before electroplating, that is, the "black sheet" of Nd-Fe-B is detected, the magnet generally needs to be aged and demagnetized again before the next process.

• Testing of electroplating products

When qt-800 measures the electroplated finished products, in order to prevent the test bench and guide rail from scratching the sample surface, silk or soft paper with less thickness can be used to pad the test bench, and the guide rail can be wrapped with silk or soft paper with less thickness.

    The temperature change will have an impact on the sealed standard sample, generally a few thousandths. Qt-800 has high detection accuracy, and the detection repetition error can reach one thousandth. If the random error is minimized, the detection repetition accuracy can reach three thousandths. Therefore, the measured value of qt-800 will reflect the slight change of magnet performance with temperature. This problem may be found in the use of the instrument: hold the same NdFeB standard sample for continuous measurement. It is found that the indication is always slightly larger at the beginning, and then the indication of the instrument becomes smaller gradually. This is not because qt-800 drifts, but because neodymium iron boron used as a sample is held in hand for a long time, and its magnetic flux decreases with the increase of temperature, so the indication of qt-800 also decreases.