在某一pH值条件下，当胶体所带负电荷和正电荷的数量相等时，胶体的净电荷为零，这就是该土壤胶体的等电点pH值。 铁、铝三氧化物含量高的土壤电荷零点较高；硅酸盐矿物或者是有机质含量高的土壤电荷零点较低
土壤可变负电荷量、阴离子吸附量和电荷零点随海拔升高而趋于增加。
The variable charge amount, the anion adsorption amount and the PZC values of the soils tend to increase with the increase in altitude.
在测量一个器件，如电容器上的电荷时，重要之点是要首先关闭静电计的零点检查功能，然后再将电容器连到高阻抗输入端。
When measuring the charge on a device such as a capacitor, it's important to disable the zero check of the electrometer first, and then connect the capacitor to the high impedance input terminal.
电荷测量：讨论电荷测量中的误差来源和尽量降低误差的方法、零点检查和电荷测量功能的扩展。
Charge Measurements: a discussion of the error sources and ways to minimize them, zero check, and extending the range of the charge function.
应用推荐