1. Before using a pressure gauge, the gauge needle starts from zero. Firstly, explain a special situation. For some pressure gauges with lower range but larger outer diameter, the above situation only occurs when lying flat. However, when the pressure gauge is vertical, the pointer returns to zero. In this case, the pressure gauge pointer cannot start from zero and should be considered a qualified product. 2. Negligence and non-standard operations during the production process. Let's talk about assembly first. During the assembly process, some screws for installing accessories were not tightened. During logistics transportation, strong vibrations or human damage can cause the above situations. For example, the upper and lower layers of the movement, dial, movement, and connector are not tightened in place, which may cause the pressure gauge pointer to zero during transportation. 3. When checking the pressure gauge, the pin is not secure. Similarly, during logistics transportation, the stainless steel pressure gauge pointer may not return to zero due to remote, uneven roads, or some human factors. If the pressure gauge is normal in the hands of consumers, what aspects should be paid attention to when using it? 1. On site use is the touchstone for checking the quality of pressure gauges. Due to the diversity and complexity of the working environment, and the intense vibration of the working environment, it is impossible to withstand severe vibration during use, although pressure gauges also have a limit value. However, if the screws of the pressure gauge are not tightened in place before leaving the factory, it can cause the tension rod to loosen, the dial to be misaligned, and movement, all of which can directly cause the pressure gauge pointer to start from zero. 2. Improper user operation, excessive pressure exceeding the range limit of the pressure gauge or even twice, can result in deformation of the spring tube, inelastic deformation, or detachment of the fan teeth of the movement. As the saying goes, "the pressure gauge is damaged", but in fact, excessive pressure during operation causes the pressure gauge pointer to not return to zero. 3. Due to the continuous force generated by the elasticity of the spring tube in the pressure gauge, even if operated properly, after a long period of use, the pointer of the pressure gauge will still shift to zero. This situation usually occurs in pressure gauges with a large range of over 10MPa.