微风速标准装置的建立和热线风速仪校准方法的实验研究

The low air speed reference facility is established at NIM of China, based on the device, the experiment on calibration of hot wire anemometer is investigated.The facility is described in detail and the calibration method for hot wire sensor is introduced. Based on the reciprocity principle, the sensor probe is mounted on the carriage that slides with consistent speed and the sliding stroke is measured by laser interferometer accurately during calibration process. The velocity measurement is therefore traceable to the measurement of length and time primary standards, additionally, the parameters of static equation is obtained according to theoretical module of hot wire sensor, the experimental results are consistent with theoretical equation. The experimental results and uncertainty analysis show that the expanded uncertainty of the breeze standard device is U=0.82%(k=2), and the expanded uncertainty of calibration result of hot wire anemometer is U=2.42%(k=2).