课本介绍的密度计是一根上部标有刻度的形状特殊的玻璃管,在管的下部玻璃泡内装入小铅丸或水银,其不足之处:它不能测体积很小的液体的密度.它的刻度不均匀,测不同液体的密度精确度不同.它分为重表、轻表两种,测未知液体的密度需选择不同的密度计.我们在教学中,经多次实验,制作了一种新型密度计,克服了上述的不足. The densitometer introduced in the textbook is a specially shaped glass tube with an upper scale mark. The small lead pellets or mercury in the lower glass bulb of the tube is inadequacies: it cannot measure the density of a very small liquid. The scale of the uneven, measuring the accuracy of different liquid density is different. It is divided into two kinds of heavy table, light table, the density of unknown liquids need to choose different densitometers. We have made a number of experiments in teaching A new type of density meter overcomes the above deficiencies.