Agilent Technologies B1500A Training Manual page 106

ULTRA LOW CURRENT
Range and Integration Time
In this example we are measuring Id very accurately. The B1500A autoranges every decade of
current down to 1 nA as a factory default. Change this to AUTO or LIMITED 10 pA to get two
more ranges of low end resolution (1 fA resolution). The factory default of LIMITED 1 nA gives
100 fA resolution and is adequate for most measurements. Since the B1500A can trade off speed for
resolution, you get better speed performance by limiting current ranging.
If your prober environment is not ultra low noise, you can remove some random noise by setting long
integration time.
Lowest resolution: Auto or Limited 10 pA
Set long integration time
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Module 6
Low Current Measurement