To make the measurement, a constant voltage is applied for a prede fined period, usually 60 seconds, and the resulting current is measured with a picoammeter or electrometer.

• 为了进行测量，在预定的时间（通常为60秒钟）内，给样品施加恒定的电压。然后，用皮安计或静电计测量产生的电流。