Variable-diameter negative pressure type breeze speed calibration device

Abstract

The invention discloses a variable-diameter negative pressure type breeze speed calibration device, which comprises a variable-diameter standard flow tube, a diverging rectification air tube, a standard air duct, a static pressure box, a centrifugal fan, a frequency converter and a micro-differential pressure meter. The variable-diameter standard flow tube is arranged on an air inlet end of the device and connected with the diverging rectification air tube which is connected with the standard air duct, the standard air duct is connected with the static pressure box through a flange, the static pressure box is connected with a centrifugal fan suction inlet through a hose, and the centrifugal fan is connected with the frequency converter through a cable. A static pressure collection hole is arranged on the variable-diameter standard flow tube and connected with the micro-differential pressure meter through a rubber tube, and wind speed measurement holes are arranged on the standard air duct. The variable-diameter negative pressure type breeze speed calibration device utilizes the variable-diameter standard flow tube to measure air flow, different tube diameters can be selected according to a measurement calibration range, and then the breeze speed section can be accurately calibrated. The micro-differential pressure meter is utilized to perform differential pressure measurement so that the data measurement is fast and accuracy.

Description

technical field [0001] The invention belongs to the technical field of wind speed calibration, and relates to a micro wind speed calibration device, in particular to a variable diameter negative pressure micro wind speed calibration device. Background technique [0002] The hot wire anemometer must be calibrated when it leaves the factory, and it needs to be calibrated after working for a certain period of time, but it is very difficult to calibrate for low wind speed (V>3m / s). At present, there are two commonly used anemometer calibration methods in the industry: one is the rotary arm machine method, which has a complex structure, especially the static air that is easy to disturb, and affects the calibration accuracy; the other is the relative calibration method, which is It is not easy to achieve low wind speed calibration and correction below 1.0m / s, and relative calibration will also bring certain errors. In addition, the change of wind speed will cause the instabili...

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Problems solved by technology

The problem is that, first, when this device calibrates the wind speed, when the wind speed V<0.6, the reading of the inclined differential pressure gauge has effectively deviated from the measurement range due to the low static pressure difference at the inlet, which has caused problems for calibration and correction. The second is that when the calibration wind speed is low, the air volume of the standard flow tube changes little, and the measured static pressure change is not obvious enough, and the measurement results are greatly affected, which in turn affects the calibration accuracy; the third is that the micromanometer used The measurement range is too large, making it difficult to guarantee the accuracy of the calibration

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