Food metal detection opportunities are affected by product effects. There are certain product effects (material effects) in all tested products. Some of them are large or small. If the size of material effects is too large to exceed the acceptance range of metal detectors, it will undoubtedly lead to a linear decline in the performance of the detectors, although at present metal effects exist. The detectors all have the function of product effect suppression, but they all have certain limitations. After digital signal processing by digital circuit, the full digital metal detector can offset the product effect to a certain extent, so as to reduce the impact of material effect on the metal detector in the working process. Metal detectors with product effect suppression function have better adaptability and higher detection accuracy compared with machines without this function.
AOTENG metal detector has the function of automatic setting. After the product passes through the detection head, the system automatically analyses the product characteristics, and automatically calculates the detection parameters, including the product effect suppression parameters. Using the recorded data of product effect characteristics previously saved, the detector system can intelligently identify the difference between metal and material effects, thus improving the performance of metal detector. In addition to the special customization of the product testing machine model for aluminium film packaging (aluminium foil) packaging, the machine can achieve relatively good detection performance after product effect suppression.
At present, the detectors on the market will use a variety of frequencies, and the product effects of different frequency devices will be different, and the effects of different humidity materials are also quite different. Therefore, it is particularly important to select metal detectors of different frequencies according to different products. Appropriate frequencies can greatly improve the detection accuracy of detectors. However, there is a widespread problem, that is to say, improving the sensitivity of detecting non-ferromagnetic metals (such as stainless steel) often results in the reduction of the accuracy of ferromagnetic metals (such as iron), and vice versa.
Integrating multiple frequencies into the same metal detector is a trend, which can complement the advantages of low frequency and high frequency. This method is a compromise technical scheme so far. Although it can achieve certain practical results, both ferromagnetic and non-ferromagnetic metals have improved detection accuracy. But for stainless steel metals, the improvement of accuracy is relatively limited.
In addition, the size of product effect is not only related to the conductivity or electromagnetic characteristics of the product to be tested, but also to the volume and weight of the product. When the product characteristics are fixed, the larger the product packaging size, the greater the material effect will become, which will affect the detection sensitivity of the testing machine.