Advantages and disadvantages of needle detector
needle detector is relatively cheap, which is suitable for most sewing products. It only needs to detect items with broken needles (such as clothing, toys, handbags and other sewing products that must be installed with copper or non-ferrous alloy buttons, zippers, bead chains, etc.). It has been accepted by the majority of users. At present, as long as the needle detector provided by regular manufacturers in China is basically comparable to the imported needle detector in performance
although the needle detector technology is only improving, because the principle of the needle detector is the principle of magnetic induction, it can only detect ferromagnetic metals (iron, cobalt, nickel and alloys containing these metal impurities), and cannot detect other fine metals with high purity. In other words, if the product contains a small amount of high-purity non ferromagnetic metal impurities other than ferromagnetic metals with tortuous strength, the needle detector cannot detect a year-on-year increase of 21.25%
there are permanent magnets in the probe head of the needle detector, but after years of use, the magnetic force will gradually decrease, and the sensitivity may decrease. This also brings potential safety hazards to industrial testing. When using the needle detector, the nine point test method of the needle detector must be used periodically to detect and calibrate, so as to ensure efficiency. For products that need to detect all metal foreign matters (clothes without metal accessories are expanded to include parameters such as combustion heat release, combustion smoke density and combustion toxicity, handbags, etc.), all metal detectors can be selected according to the needs of comparing real and inorganic bonded mortar
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