Methods for airflow measurement using anemometers
Measurement of anemometer in pipeline
Practice has proved that the 16mm probe of the anemometer is the most versatile. Its size not only ensures good permeability, but also can withstand a flow velocity up to 60m/s. As one of the feasible measurement methods, the air flow velocity measurement in the pipeline is suitable for air measurement by the indirect measurement procedure (grid measurement method).
Anemometer Measurements in Extraction Exhaust
The vent will greatly change the relatively balanced distribution of the airflow in the duct: a high-speed area is generated on the surface of the free vent, and the rest is a low-speed area, and a vortex is generated on the grid. According to the different design methods of the grid, the airflow section is relatively stable at a certain distance (about 20cm) in front of the grid. In this case, the aperture wheel of a large anemometer is usually used for measurement. This is because the larger bore is able to average the unbalanced flow rate and calculate its average value over a larger range.
The anemometer uses a volume flow funnel to measure at the suction hole
Even if there is no grid interference at the suction point, the route of air flow has no direction, and its airflow 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. If the grid measurement method with averaging function is used for measurement, and to determine the volume flow method, only the pipe or funnel measurement method can provide repeatable measurement results. In this case, measuring funnels of different sizes can meet the requirements of use. Using the measuring funnel, a fixed section that meets the flow velocity measurement conditions can be generated at a certain distance in front of the sheet valve, and the center of the section is measured and fixed. here. The measured value obtained by the flow rate probe is multiplied by the funnel coefficient to calculate the drawn volume flow.
