Anemometric method is the most accurate and reliable technique for air velocity measurement. In present work, a voltage follower based circuit is proposed, and a low-cost sensor (tungsten filament) is chosen to perform Constant Voltage Anemometer (CVA) operation for air velocity measurement. For performing the real-time experiment, a wind tunnel featuring a rectangular section (test section I) and a circular section (test section II) with a provision for low-cost sensors and a reference Hot Wire Anemometer (HWA) was fabricated. The measurement is repeated multiple times for various air velocities in the range of 3 m/s to 12 m/s. The estimated ‘pdr’ value (ratio of the power dissipated in the sensor, P w to the difference between heated sensor resistance, R w and the sensor resistance at ambient temperature, R a ), considered as new output voltage, is analogous with the output voltage (V o ) of the proposed circuit. The range of ‘pdr’ in test sections I and II is 0.033 mW/Ω to 0.867 mW/Ω and 0.0062 mW/ῼ to 0.1059 mW/Ω, respectively. Similarly, overheat ratio, OHR (ratio of the difference between heated sensor resistance, R w and the sensor resistance at ambient temperature, R a to the sensor resistance at ambient temperature, R a ) estimated, is also found to be analogous with the change in temperature (difference between the temperature of the heated sensor T w and the ambient temperature T a ). The range of OHR in test sections I and II is 0.709 to 0.660 and 0.678 to 0.647, respectively. Uncertainty analysis is carried out for the proposed voltage follower based CVA measurement system and the expanded uncertainty with a 95% confidence level is obtained as 0.54 for the whole range of air velocity measurement.

中文翻译：

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使用替代信号调理电路实现恒压风速计

风速测量法是最准确、最可靠的风速测量技术。在目前的工作中，提出了一种基于电压跟随器的电路，并选择了低成本传感器（钨丝）来执行恒压风速计 (CVA) 操作以测量风速。为了进行实时实验，制作了一个具有矩形截面（测试截面 I）和圆形截面（测试截面 II）的风洞，并配备了低成本传感器和参考热线风速计 (HWA)。对于 3 m/s 至 12 m/s 范围内的各种空气速度，测量重复多次。估计的“pdr”值（传感器中耗散的功率 P w 与加热的传感器电阻 R w 和环境温度下的传感器电阻 R a 之差的比值），被视为新的输出电压，类似于所提出电路的输出电压（V o ）。测试部分 I 和 II 中的“pdr”范围分别为 0.033 mW/Ω 至 0.867 mW/Ω 和 0.0062 mW/ῼ 至 0.1059 mW/Ω。类似地，估计过热率 OHR（加热的传感器电阻 R w 与环境温度下的传感器电阻 R a 与环境温度下的传感器电阻 R a 之比）也与变化类似在温度（加热传感器的温度 T w 和环境温度 T a 之间的差异）。测试部分 I 和 II 中的 OHR 范围分别为 0.709 至 0.660 和 0.678 至 0.647。对所提出的基于电压跟随器的 CVA 测量系统进行了不确定性分析，获得了具有 95% 置信水平的扩展不确定性为 0。