1. Cover size (tuyere size) When the size difference between the cap air volume cover and the tuyere is large, a large measurement error will be caused, so it is necessary to use a cover with similar tuyere size for measurement. The air volume hood shall be selected according to the size and area of the air outlet to be measured, and the length of the long side of the air volume hood shall not exceed 3 times the length of the long side of the air outlet; The area of the air outlet shall not be less than 15% of the boundary area of the enclosure.
2. Check whether the air volume meter is normal, and ensure that all settings of the air volume meter meet the operating requirements.
3. Determine the placement position of the hood to cover the air outlet. The air outlet shall be located in the middle of the hood until the whole air outlet is covered by the wind hood.
4. Ensure that there is no air leakage at the air outlet, observe the display value of the air volume meter, and read the air volume value after the display value becomes stable;
5. Back pressure compensation When the air volume at the tuyere is large, the resistance of the tuyere caused by the throttling of the air volume hood and the measuring part will increase, resulting in more air volume reduction. In order to eliminate the small air volume at this part of the tuyere, back pressure compensation is required. When the air volume ≤ 1500 m ³ / H, back pressure compensation is not required, and the air volume read is the air volume value of the measured air outlet; When the air volume is ＞ 1500m ³ / H, use the back pressure compensation baffle to compensate the back pressure, and read the value displayed by the air volume meter as the measured air volume after air outlet compensation.
6. If the size of the air vent is particularly large, it is necessary to communicate with the seller in advance to customize the cover.