Hello, the piston pressure gauge dispenser, which uses a closed-loop dispensing system, works through the cooperation of the piston and the cylinder. The piston moves downward in the cavity to push the glue, and the volume of the cylinder determines the amount of glue, so that a certain amount of glue and shape can be obtained. The advantages of the invention are:the speed is faster than the previous two methods, it can deliver high viscosity fluid, the dispensing flow of the outlet can be adjusted by controlling the air pressure, the time of extruding the glue will not be changed due to the size of the dripping point, so that it can maintain a constant working efficiency, it is easier to realize fast, accurate and repeatable dripping, and it is suitable for dripping of glue solutions with different viscosities. Disadvantages are:The equipment needs to be cleaned frequently, the cleaning process is complex, the equipment investment is also large; when the glue solution contains large particles, this method is not suitable.