A check weighing scale is used to ensure that the weight of a container of the product is within predetermined limits. All packs that are outside specified limits must be taken out. Check weighing scales are mostly used in industry. A checkweighing process may also be called as tolerance weighing. There are a few ways to indicate the upper and lower limits. It depends on the model of scales and balances. Some checkweighing scales show the limits giving the visual signal (flashing different color of lights), others give audible signals. There are also a checkweighing scales which give a bar graph on their graphical display. Commonly, these scales can be found in production lines. In some applications these scales do need to be CE type approved and trade approved.