Distribution of charge in electrets

Measurements are reported of the total charge and its mean position in liquid-charged FEP electrets. A new nondestructive technique has been used. The large difference in decay rates of positive and negative liquid-charged electrets is accompanied by quite different behavior of the deposited charge as it migrates through the electret. The total volume charge density present in untreated FEP has been measured: it typically amounts to 0.1–0.6 C m−3 for 25-μ-thick material.