Measuring tools and scales Calipers can weigh objects.Measuring tools and scales Calipers can weigh objects.A small weighing instrument consisting of a wooden or metal pole with a star and taper and equipped with weights, a weight rope, and a scale pan. According to the scope of use and the size of the scale is divided into three kinds: shekel, pan scale and crochet scale. Steelyard is a first arm lever. It is a simple weighing instrument that uses the principle of lever balance to weigh weight. It consists of a wooden beam with a star, a metal hammer, and a lifting rope. The load-bearing device is a rectangular countertop, a small weighing instrument usually used on the ground. According to the structure principle, it can be divided into two categories: mechanical scale and electronic scale. Electronic platform scale: A small electronic weighing instrument using the principle of non-electrical measurement. It is composed of load bearing table, weighing body, weighing sensor, weighing display and regulated power supply. It has the characteristics of light weight, convenient movement, many functions, the display and the scale body are connected by cable, and can be placed according to the need when using. In addition to weighing, tare weight, cumulative weight and other functions, but also can be connected with the actuator, set the upper and lower limits to control the speed of feeding, can be used as small package batching scale or quantitative scale. The electronic valuation scale has the characteristics of high measurement accuracy, convenient and fast keyboard operation, and digital memory.