Mistakes in the use of metal detectors and recommended practices

Metal detector is an important product in modern industry For textile industry, clothing products have very good detection effect So what should we pay attention to when we use it? Are there any mistakes we should pay attention to? Error 1: over reliance on metal detector error analysis: the metal detector is designed according to the change principle of the magnetic field signal caused by the induction of metal in the magnetic field, which is used to detect the metal foreign matters in the product Compared with other foreign matter detection technology in products, it has the advantages of universality, easy operation and no need for special protection in the detection of metal foreign matter in products However, it also has the defects that it can only be used in the detection of metal foreign matter and the detection sensitivity is affected by many factors The metal detector has certain restrictions on the specification of the detected metal At the same time, its sensitivity will be affected by external vibration, temperature, product moisture, salt content or product temperature, individual size, component and other factors during the use process Recommended practice: the screen used by general food enterprises for screening powder and fluid raw materials, or the steel wire ball of cleaning tools, etc., cannot rely on the metal detector to control the hidden dangers caused by the damage of the screen and steel wire ball The screen metal must rely on the daily inspection of the previous process to control the potential hazards to the product The steel wire ball cannot be used in the food processing area Error 2: frequently moving metal detector Error analysis: in some food enterprises, because of the purchase cost of metal detector, the inspectors often use the same metal detector in different production lines, or frequently move the metal detector in the same water line according to different process steps to achieve the purpose of detection These phenomena are easy to make the metal detector suffer external vibration in the process of moving In addition, due to different places, the use conditions (ambient temperature, humidity, etc.) may change, which will affect the stability of metal detector operation In the long run, it is easy to cause abnormal operation of metal detector and shorten its service life Recommended practice: in order to keep the metal detector in good condition for a long time, appropriate places shall be selected for installation and fixation No external vibration, no sunlight, far away from heat source (such as furnace, heater, etc.), clean (often clean, keep less dust, Zui good dust-free), relatively stable temperature and humidity (generally at 0 ~ 40 ℃), humidity generally at 30% ~ 80%), no sharp change, no condensate condensation, etc., no volatile, corrosive, inflammable near the instrument Explosion and other substances At the same time, it should be ensured that there is no active metal material around, and it can not be installed near the existing metal detector (mutual interference, etc.) After the installation position is determined, the supporting screws shall be used to support together and the instrument shall be leveled to avoid noise or belt deviation Error 3: the time interval of metal detector operation state confirmation is arbitrary Some enterprises do not clearly stipulate the interval between two confirmations when they use standard test pieces to confirm the detection ability of metal detector The common problem is that the detection is too frequent or too sparse, and even there are frequent tests only when abnormalities are found, few tests when no abnormalities are found, or even no tests These are not conducive to the good operation of the metal detector, but also lead to the increase of the cost of correction when the product is missed or mistakenly inspected (because there is no objective evidence to prove that some of the products are qualified, but all of them need to be re inspected) Recommended practice: when the metal detector is turned on, it will run for about 20min, i.e test with standard test pieces (Fe and sus) During the operation, the sensitivity of the machine shall be adjusted before passing the product, and it shall be reconfirmed and tested with the product In the use process, the standard test piece shall be used for confirmation once every 30-60min At the end of product passing, the standard test piece shall also be used for confirmation In this way, the metal detector can not only keep normal working state in the use process, but also ensure that the corrective measures can be easily and economically implemented when the product is abnormal When testing the metal detector with standard test piece, the correct method should be: put the standard test piece in the left, middle and right positions of the belt to pass through the channel of the metal detector, and use the auxiliary without interference (such as rubber box, etc.) to assist the detection energy Zui weak area of the metal detector, so as to ensure that the metal is different when the product passes within the detection capacity of the metal detector The substance was detected successfully After these steps are completed, the standard test piece shall be attached to the product that has been confirmed to be qualified, and then the previous step shall be repeated Only after all of them are qualified and recorded can the daily operation status of metal detector be confirmed If you use metal detector, you can pay attention to the above points, I believe that it will have a very good effect on your normal detection.