Zock J P
Pflugers Arch. 1981 Oct;391(4):345-52. doi: 10.1007/BF00581522.
Some aspects of the linearity and the frequency response of flow measurement with Fleisch type pneumotachometers are considered. The transition from a uniform velocity distribution at the entrance of the capillary tubes of the transducer to a fully developed flow profile is discussed as one of the phenomena influencing the linearity of the set-up. Besides, an expression is derived for the frequency response of the Fleisch pneumotachometer. The frequency responses as derived from measurements show good agreement with theory. In the range of the lower frequencies the frequency response of the flow measuring set-up is proved to be largely determined by the frequency response of the pressure transducer with the connecting tubes. A simple way is indicated to measure the latter. This, in combination with the calculated frequency response of the flow transducer, makes it fairly easy to determine the frequency response characteristics of a flow measuring set-up containing a Fleisch type pneumotachometer.
本文考虑了使用弗莱施型呼吸流速计进行流量测量时的线性度和频率响应的一些方面。讨论了换能器毛细管入口处从均匀速度分布到充分发展的流动剖面的转变，这是影响测量装置线性度的现象之一。此外，还推导了弗莱施呼吸流速计的频率响应表达式。测量得出的频率响应与理论结果吻合良好。在较低频率范围内，流量测量装置的频率响应在很大程度上由压力传感器及其连接管的频率响应决定。文中指出了一种测量后者的简单方法。这与流量传感器计算出的频率响应相结合，使得确定包含弗莱施型呼吸流速计的流量测量装置的频率响应特性变得相当容易。
