毕托管测速

将实验数据整理成下表:实验次序上下游水位差(cm)毕托管水头差(cm)测点流速(cm/s)测点流速系数H1H2AHH3H4Ah136.415.221.215.736.420.7202.63570.994066236.415.121.315.736.420.7202.63570.99173336.415.121.315.736.420.7202.63570.99173436.415.121.315.736.420.7202.63570.99173536.315.121.215.736.420.7202.63570.994066636.315.121.215.736.420.7202.63570.994066736.315.121.215.736.420.7202.63570.994066836.415.121.315.636.520.9203.61220.996509936.51521.515.736.6520.95203.85560.9930491036.61521.615.736.721204.09880.9919291136.61521.615.7536.720.95203.85560.9907481236.6514.921.7515.536.721.2205.06840.9931991336.614.921.715.536.721.2205.06840.9943431436.71521.715.936.720.8203.12450.9849171536.515.0521.4516.336.720.4201.16190.9810691636.61521.61836.718.7192.59790.9360351736.61521.624.436.712.3156.20080.7591431836.61521.63636.70.737.263160.1811011936.61521.636.636.70.114.084150.068452036.61521.636.636.70.114.084150.06845六、实验分析与讨论1.利用测压管测量点压强时，为什么要排气？怎样检验排净与否?答：毕托管、测压管及其连通管只有充满被测液体，即满足连续条件，才有可能测得真值，否则如果其中夹有气柱，就会使测压失真，从而造成误差。误差值与气柱高度和其位置有关。对于非堵塞性气泡，虽不产生误差，但若不排除，实验过程中很可能变成堵塞性气柱而影响量测精度。检验的方法是毕托管置于静水中，检查分别与毕托管全压孔及静压孔相连通的两根测压管液面是否齐平。如果气体已排净，不管怎样抖动塑料连通管，两测管液面恒齐平。毕托管的压头差厶h和管嘴上下游水位差△H之间的大小关系怎样？为什么？答：△h