Laboratory experiments are developed to measure the electrostatic charge of individual particles lofted into air by electrostatic forces. By tracking the magnitude of charges on the sand particles as they move, it can be inferred that no discharge occurs within a full trajectory. The distribution of particle charge is related to particle size, as well as conditions such as the electric field and relative humidity. We now show that our experimental results for particle charge can be accurately predicted by theory without any fitting parameters. The excellent agreement between theory and experiment shows that the experimental methodology developed here is accurate. Furthermore, the results provide direct evidence for the previously proposed idea that sand particles lofted in an electric field behave like conducting particles, due to conducting water layers that arise from ambient humidity, and gain their charge by induction in an electric field. This electrostatic process will occur in natural sand and dust storms, and the enhanced dust loading will have atmospheric and climate implications.

开发了实验室实验来测量通过静电力放到空气中的单个颗粒的静电荷。通过跟踪沙粒移动时沙粒上电荷的大小，可以推断出在整个轨迹内没有放电发生。颗粒电荷的分布与颗粒大小以及诸如电场和相对湿度之类的条件有关。现在我们表明，无需任何拟合参数，理论上就可以准确预测我们的粒子电荷实验结果。理论与实验之间的极好的一致性表明，这里开发的实验方法是准确的。此外，结果为先前提出的想法提供了直接的证据，即由于在环境湿度下产生的导电水层，在电场中放出的沙粒的行为类似于导电粒子，并通过电场感应获得其电荷。这种静电过程将在自然的沙尘暴中发生，并且增加的粉尘负荷将对大气和气候产生影响。