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Misunderstandings in the use of metal detectors and recommended practices

Misunderstandings in the use of metal detectors and recommended practices

Issue Time:2020-10-27

Metal detectors machine is a more important product in modern industry. For the textile industry, clothing products have very good detection results, so what should we pay attention to when using it? Are there any misunderstandings that we should pay attention to?


  Misunderstanding 1: Too much dependence on metal detectors machine

   Misunderstanding analysis: The metal detectors machine is designed according to the principle of the change of the magnetic field signal caused by the induction of the metal in the magnetic field, and is used to detect the metal foreign matter in the product. Compared with other foreign body detection technologies in products, it has the advantages of versatility, easy operation, and no need for special protection in the detection of metal foreign bodies in products, but it can only be used for metal foreign body detection and detection sensitivity is affected by many factors. Impact and other defects. Metal detectors have certain restrictions on the specifications of the detected metals. At the same time, during use, its sensitivity will also be affected by factors such as external vibration, temperature, product moisture, salt content, or product temperature, individual size, and composition. .

Recommended practice: General food companies use screens for sieving powder and fluid raw materials, or steel balls for cleaning tools, etc. You cannot rely on metal detectors machine to control the damage caused by screens and steel balls. The hidden dangers caused. The metal of the screen must be controlled by the daily inspection of the previous process to control the hidden dangers that it may cause to the product, and steel balls cannot be used in the food processing area.


Misunderstanding 2: Frequently move metal detectors machine

Misunderstanding analysis: In some food companies, because of the purchase cost of metal detectors, inspectors often use the same metal detector on different production lines, or move the metal detector frequently in the same assembly line according to different process steps. For the purpose of detection, these phenomena are likely to cause the metal needle detector to be exposed to external vibrations during the movement; in addition, because it is placed in different places, the use conditions (ambient temperature, humidity, etc.) may change, which will affect the operation of the metal detector. stability. If things go on like this, it is easy to cause abnormal operation of the metal detector and shorten its service life.

  Recommended practice: In order to keep the metal detectors machine in good condition for a long time, choose a suitable place for installation and fixation. It is required to have no external vibration, no sunlight, far away from heat sources (such as stoves, heaters, etc.), clean (frequently clean, keep less dust, preferably dust-free), relatively stable temperature and humidity (temperature generally 0-40 ℃), Humidity is generally 30%~80%), there should be no sharp changes, no condensation of condensed water, etc., and no volatile, corrosive, flammable and explosive substances near the instrument. At the same time, it should be ensured that there are no moving metal materials around, nor can it be installed near the existing metal needle detector (mutual interference, etc.). After the installation position is determined, the support screws should be used to support them together and the instrument should be adjusted to a level to avoid noise or belt deviation.

  Misunderstanding 3: The time interval for confirming the running status of metal detectors machine is arbitrary

   Misunderstanding analysis: Some companies do not clearly specify the interval between two confirmations when using standard test pieces to confirm the detection capability of metal detectors machine. The common problem is that the detection is too frequent or too sparse. There are even cases where frequent testing is performed when abnormalities are found, and there are few or even no tests when abnormalities are not found. These are not conducive to the good operation of the metal detector, and will also increase the cost of correcting the product when the product is missed or misdetected (because the time or time of the abnormal occurrence cannot be confirmed, there is no objective evidence to prove that some of the products are qualified, and all of them need to be re- test).

  Recommended method: When the metal detectors machine is turned on, run for about 20 minutes, that is, use standard test pieces (Fe and SUS) for detection. During operation, the sensitivity of the machine should be adjusted before the product is passed, and then re-confirmed and tested with the product. In the process of use, the standard test piece is used to confirm every 30~60min. When the product passes, it is also necessary to use the standard test piece to confirm. This not only ensures that the metal detectors machine always maintains normal working conditions during use, but also ensures that corrective measures can be implemented conveniently and economically when abnormalities occur through the product. When using a standard test piece to test a metal detector, the correct method should be: put the standard test piece on the left, middle, and right of the belt and pass through the channel of the metal detectors machine, and use non-interfering auxiliary materials (such as plastic boxes, etc.) ) Assist in passing through the weakest area of ​​detection capability of metal detectors machine to ensure that metal foreign objects are detected smoothly when the product passes within the detection capability of metal detectors machine. After completing these steps, the standard test piece should be attached to the product that has been confirmed to be qualified, and then repeat the previous step. It is only once the daily metal detector operation status confirmation is completed after all qualified and recorded.


   If you are using metal detectors machine, you can pay attention to the above points, I believe it will have a very good effect on your normal detection.

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