The resistance of the suction end of the micro air pump is a relatively complex and variable parameter, which is affected by many factors, such as the type of pump, the length of the pipeline, the degree of bending of the pipeline, the size of the aperture in the pipeline, and the type of load connected to the pump. Therefore, it is impossible to give a uniform and specific extraction end resistance value.
In the selection, to determine whether the suction end resistance of the micro-air pump is suitable, it is usually necessary to compare the actual resistance value with the technical parameter of the pump, "Maximum allowable resistance of the air inlet" (Por value). This Por value is determined by the manufacturer during the design and testing process and represents the maximum resistance that the pump can withstand at the pumping end.
In general, if the resistance of the extraction end is small, then you can choose a gas sampling pump, because it can only carry a small load, but the price is relatively cheap. However, if the resistance of the pumping end is large, or the pump needs to work in the case that the pumping end allows large resistance or even complete blockage, then it is necessary to choose a micro-vacuum pump in the strict sense, which is slightly more expensive, but has a stronger load capacity.
The following are some empirical methods to judge the size of the suction end resistance:
Pipeline length and bending degree: if the pump's pumping end is connected to a long pipeline, or the pipeline has more bending points, bending strongly, and may even block and close, then the resistance is larger.
Pipe diameter: When the pipe hole is very small (such as less than φ2 mm), it will also increase the resistance of the extraction end.
Pipelines and load components: there are throttle valves, solenoid valves, air switches, filters and other components on the pipeline, or the pump air outlet is connected with the closed container, and the pump air outlet is connected with the filter container and the container port is placed with the filter screen, which will increase the resistance of the air outlet.
In order to accurately select, in addition to considering the resistance of the extraction end, it is also necessary to consider the requirements of the exhaust end resistance, flow rate and vacuum degree. In the defined optional series, the final model is determined according to the specific needs. At the same time, it is also necessary to pay attention to the parameter selection to leave a margin, especially the flow parameter, because after the pump is connected to the gas path system, the gas path components such as pipes and valves will cause pressure loss, thereby attenuating the flow rate.
In general, the suction end resistance of the micro-air pump is a parameter that needs to be comprehensively considered according to the actual situation and the technical parameters of the pump. In the selection, it is recommended to consult the manufacturer or professional in detail to ensure that the selected pump can meet the actual needs.