Introduction
Low current measurement is a key performance metric for picoammeters and
electrometers, which often specify atto-ampere (aA) level current measure-
ment resolution. In addition to ultra-low current measurement capability, it is
also very important to have other measurement functions such as iltering to
smooth-out noisy data and basic measurement data evaluation tools to simplify
debugging.
The four key capabilities necessary to successfully make sensitive low current
measurements are listed below:
1. Femto-ampere current measurement capability.
2. A loating design coniguration for maximum lexibility.
3. The ability to improve data quality through averaging, iltering and zero
cancelation.
4. Integrated capability to analyze measurement data via histograms, time
domain graphs, etc.
The Keysight B2981A/B2983A Femto/Picoammeter and B2985A/B2987A Elec-
trometer/High Resistance Meter provide both superior performance of 10 aA
minimum resolution and improved measurement conidence by supporting all of
the features listed above.
This technical overview highlights the B2980A Series ammeter current mea-
surement performance using a diode measurement example.
Note: The B2983A and B2987A have an internal rechargeable battery that allows them to
operate without being connected to AC power.
Important words used in
the document:
–
Low-current metric system
preixes:
–
pico (p)= 10
-12
–
femto (f)= 10
-15
–
atto (a)= 10
-18
