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我们熟知的液体比重测定法已有好几种,但欲得到准确与精密的结果倒是一个大难题。最近美国化学会所发表的测定液体比重新法解决了这个困难,它的操作既简捷,结果又准确。这个发明在化学工业的发展史里将占一重要地位,因为它的精细结果能准确到小数点後第四位,除掉这几个优点外,仪器的装置非常简单,操作的人不需经过特殊的训练。仪器的装置是一个直径相等的细长弯玻璃管,管的两端垂直平行,下端安插入烧杯A与B内,两管间置一米突尺,管的顶部中点则与一真空抽气机(Vacuum pump)相衔接。烧杯A内盛已知比重之液体(Sp.gr.A.),烧杯B内置欲测比重之液体(Sp.gr.B.)。装置就绪後,将玻璃管内之空气,用抽气机徐徐抽出,烧杯内之液体则因管内之空气排出而上升,共上升之速度与液体之重量成反。比待升至
We are familiar with the determination of liquid specific gravity has several, but to get accurate and precise results is a big problem. The recent decision by the American Chemical Society to determine the liquid specific gravity has solved this difficulty by simplifying its operation with accurate results. This invention will occupy an important position in the history of the chemical industry because its fine results can be accurate to the fourth place after the decimal point. Apart from these advantages, the apparatus of the instrument is very simple and the operator need not go through special Training. The device is a slender curved glass tube with the same diameter. The two ends of the tube are vertically parallel. The lower end is inserted into the beakers A and B. The middle of the top of the tube is provided with a vacuum pumping Vacuum pump. Beaker A contains a known proportion of liquid (Sp.gr.A.), and Beaker B contains a liquid to be measured (Sp.gr.B.). After the device is ready, the air in the glass tube is slowly drawn out by a suction machine. The liquid in the beaker rises due to the air discharged from the tube. The total speed of the rise is opposite to the weight of the liquid. Than to be raised to