A low-cost and simple setup to measure the densities of liquids is introduced herein. The results and reliability of this setup were evaluated for pure liquids, water–ethanol binary mixtures, and aqueous NaCl solutions. The constructed densitometer provided density values with acceptable relative errors (less than ±3.0%), which were compared to estimates of density from the literature. The favorable agreement is surprising for such a simple and low-cost setup. The facile design lends itself to use in diverse teaching environments to reinforce the ubiquitous concept of density at the secondary-school level and for undergraduate physical-chemistry teaching laboratories.

中文翻译：

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简单且低成本的设置，用于测量液体的密度

本文介绍了一种用于测量液体密度的低成本且简单的装置。对于纯液体，水-乙醇二元混合物和NaCl水溶液，评估了该设置的结果和可靠性。所构建的密度计提供的密度值具有可接受的相对误差（小于±3.0％），并将其与文献中的密度估计值进行了比较。这种简单且低成本的设置令人赞叹的协议令人惊讶。灵活的设计使其可以在多种教学环境中使用，以强化中学级和本科生物理化学教学实验室普遍存在的密度概念。