Measurement of the anemometer in the intake and exhaust of the air:
The vent will greatly change the relatively balanced distribution of air flow in the pipe: a high-speed area will be generated on the surface of the free vent, and the remaining parts will be low-speed areas, and a vortex will be generated on the grid. Depending on the different design methods of the grid, the airflow cross section is relatively stable at a certain distance (about 20cm) in front of the grid. In this case, a large anemometer's aperture wheel is usually used for measurement. Because a larger diameter can average unbalanced flow rates and calculate their average value over a larger range.
The anemometer uses a volumetric flow funnel at the air extraction hole to measure:
Even if there is no grid interference at the exhaust point, the air flow path has no direction, and its air flow cross section is extremely uneven. The reason is that the partial vacuum in the pipeline draws the air into the air chamber in a funnel shape. Even in the area very close to the air extraction, there is no position that meets the measurement conditions for measurement operations. Only the pipe or funnel measurement method can provide reproducible measurement results, such as using a grid measurement method with an average calculation function and using it to determine the volumetric flow rate. In this case, measuring funnels of different sizes can meet the usage requirements. A measuring funnel can be used to generate a fixed section that meets the flow rate measurement conditions at a certain distance in front of the sheet valve. Measure and locate the center of the section and fix the section. Measure and locate the center of the section and fix it. Measure and locate the center of the section and fix it. Here it is. The measured value obtained by the flow rate probe is multiplied by the funnel coefficient to calculate the pumped volumetric flow rate. (e.g. funnel coefficient 20)
