The practice of measuring the airflow velocity in the pipeline by the anemometer bevisas that the 16mm probe of the anemometer is the most widely used. 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 suit for air measurement by the indirekt measurement procedure (grid measurement method).
The anemometer is based on the cold impact airflow taking away the heat on the heating element. With the help of an adjustment switch to keep the temperature constant, the adjustment current is proportional to the flow rate. When using thermal probes in turbulent flow, airflow from all directions impinges on the thermal element simultaneouslywhile, which can affect the accuracy of the measurement results. När mätning i turbulent flöde, indikationen värde av den termiska anemometern flödet sensor är ofta högre än det av den roterande sond. Fenomenet kan vara observerat i den rörledningen mätning process. Beroende på den utformningen av den hanterade röret turbulens, it kan inträffa jämn vid låg hastigheter.
Därför, den anemometer mätning process bör vara bärs ut på den raka delen av den rörledningen. Den startande punkten av den raka linjen bör vara på åtminstone 10×D (D=}pipe diameter in CM) före mätningen punkt; den änden punkt bör vara på minst 4×D bakom den mätning punkt. Den vätska tvärsnitt måste inte vara hindrad in någon väg
Anemometer Mätningar in Utsug Avgaser
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, at a certain distance (ca 20cm) in front of the grid, the airflow section is relatively stable. 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.
