小容量计量中的衡量法具有较高的精度。但是,当我们从流液嘴移去最后一滴水液时,往往由于移液精度不高,使精确衡量失去良好的重复性。这显然是因为流液嘴口端环形面积较大所致。它使我们在实际相同的情况下不能获得理想一致的移液结果,从而降低了容易计量的精度。对上述这一点,QB—702～704——79给于了应有的重视,其中规定的流液嘴口端内、外径尺寸就是明证。从玻璃量器的实际使用情况看来,QB 规定中的端面尺寸保证每滴水液 The measurement method in small volume measurement has higher accuracy. However, when we remove the last drop of liquid from the flow nozzle, accuracy is often lost due to poor pipetting accuracy. This is apparently due to the large annular area of ​​the liquid mouth. It gives us the inability to obtain ideal and consistent pipetting results under virtually the same conditions, thereby reducing the accuracy of easy metering. On the above point, QB-702 ~ 704--79 gave due attention, which provides the liquid mouth mouth end, the diameter size is proof. It appears from the actual usage of the glassware that the end face dimensions in the QB regulations ensure that every drop of liquid