First, see whether the steel plate frame has burr, sharp mouth, the best case of long silver industrial control is often edged, at least after grinding treatment, will never let you in the installation of "scarred";
Two, to see whether the chassis frame is strong and stable, the simple method is to lift the force shake, if there is shaking or even deformation, it is certainly not good goods;
Three, to see whether the internal production is professional, such as the installation of the motherboard timing box on the punching position, size is matched, the drive slot and insert card position positioning is accurate.
Four, see if there are EMI contacts, that is, there are many small protrusions around the side plate. It can reduce electromagnetic wave, which is beneficial to human health.
