Keithley SourceMeter 2400, Service Manual, Page: 19 / 137

2400-902-01 (G - Feb 2006)
1-7 Model 2400 Series User’s Manual
Performance Verification
The “real” compliance condition can occur when the compliance setting is less than the highest
possible reading of the measurement range. When in compliance, the source output clamps at
the displayed compliance value. For example, if the compliance voltage is set to 1V and the
measurement range is 2V, the output voltage will clamp (limit) at 1V.
“Range” compliance can occur when the compliance setting is higher than the possible reading
of the selected measurement range. When in compliance, the source output clamps at the
maximum measurement range reading (not the compliance value). For example, if the
compliance voltage is set to 1V and the measurement range is 200mV, the output voltage will
clamp (limit) at 210mV.
Maximum compliance values
The maximum compliance values for the measurement ranges are summarized as follows:
Measurement
range
Maximum
compliance value
200mV
2V
20V
200V
1µA
10µA
100µA
1mA
10mA
100mA
1A
210mV
2.1V
21V
210V
1.05µA
10.5µA
105µA
1.05mA
10.5mA
105mA
1.05A
When the SourceMeter goes into compliance, the “Cmpl” label or the units label (i.e., “mA”)
for the compliance display will flash.
Determining compliance limit
The relationships to determine which compliance is in effect are summarized as follows. They
assume the measurement function is the same as the compliance function.
• Compliance Setting < Measurement Range = Real Compliance
• Measurement Range < Compliance Setting = Range Compliance
You can determine the compliance that is in effect by comparing the displayed compliance
setting to the present measurement range. If the compliance setting is lower than the maximum
possible reading on the present measurement range, the compliance setting is the compliance
limit. If the compliance setting is higher than the measurement range, the maximum reading on
that measurement range is the compliance limit.