Autoranging - QuadTech Guardian 2500 Series Instruction Manual

If Enhanced Features is set for Off, press
right arrow key to select Adaptive DC Ramp.
Press up/down arrow keys to select Adj. V During Test, Off, On.
Press the UTILITY key to exit, or move to other Utility functions with the

13. Autoranging

Selection for autoranging is Full, None, or Limited. The selection Limited is
recommended for normal applications.
Hipot Autoranging
There are two ranges available for Hipot testing, the switchover point from low (more sensitive)
to high (least sensitive) is 500 µA for AC Hipot and 200 µA for DC Hipot. For Full, the range
selected is the more sensitive one if the current is less than this value, independent of the
programmed high limit. For None, the range selected is always the least sensitive, and for
Limited the range is determined by the programmed high limit.
IR Autoranging
The Guardian 2530 uses seven ranges of sensitivity for the current input to cover its IR range of
10 kohms to 2000 Gohms. The lowest resistance which can be measured in any range must be
high enough to give an input current which will not overload the signal processing circuitry at
the programmed test voltage. The highest resistance which can be measured in any range must
allow enough current for accurate measurement, which is considered to be about 1% of the full
scale current. Both the maximum and minimum resistances are thus proportional to the test
voltage.
During the ramp phase of an IR test, the current channel is in the least sensitive range. If
autoranging is enabled, the sensitivity of the current channel will be increased step by step as the
charging current drops. The highest range which will be reached is determined by the current
through the DUT and will be the range at which the DUT IR can be measured with the highest
accuracy. This insures that the IR of purely resistive DUTs can be accurately measured up to
2000GΩ.
Operation/Programming
Adaptive DC Ramp
On
Adaptive DC Ramp
On
up/down arrow key to select On and press
Util
Util
right arrow key.
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