一、测量原理针阀外径分级气动测头的测量原理是把针阀直径尺寸的变化转换为通过带有锥度的环形气隙的空气流量的变化。当这种空气通过带锥度的玻璃管时,流量的变化就使得浮在玻璃管内的浮标的位置发生相应的变化。工作时,使测杆的测头尖端接触针阀外圆最高点(图1),针阀 First, the measurement principle Needle valve diameter grading Pneumatic probe measurement principle is to change the needle diameter size changes through the air flow with a tapered annular air gap changes. When this air passes through the tapered glass tube, the change in the flow rate changes the position of the float floating in the glass tube. Work, the probe tip of the measuring rod contact the highest point of the outer cylindrical needle (Figure 1), needle valve