Model 6487 Reference Manual
Range, Units, Digits, Rate, and Filters
4-3
Autorange limits
Search time for amps can be reduced by setting upper and/or lower autorange limits. For
example, if you know the maximum input will be around 1µA, set the upper current range
limit to 2µA. This eliminates the 20µA, 200µA, 2mA, and 20mA ranges from the search,
thereby increasing the range change speed. Should the input exceed 2.1µA, the
OVRFLOW message will be displayed.
Perform the following steps to set upper and/or lower autorange limits.
1.
Press CONFIG key (CONFIGURE: will be displayed).
2.
Display the desired limit (UPPER or LOWER):
a.
Press the RANGE
key to display the present UPPER range limit.
b.
Press the RANGE key to display the present LOWER range limit.
3.
Scroll through the available range limits using the or RANGE key.
4.
Press ENTER when the desired range is flashing.
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If you attempt to select an incompatible range limit, it will be ignored and TOO
LARGE or TOO SMALL will be displayed briefly. For example, if the lower
range limit is 20µA, trying to set the upper limit to 2µA will result in the TOO
SMALL error.
Units
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Changing the display resolution is not allowed if displaying readings in scien-
tific notation.
Readings can be displayed using engineering (ENG) units (i.e. 1.236 mA) or scientific
(SCI) notation (i.e. 1.236E-03A). Perform the following steps to change the units setting:
1.
Press MENU key.
2.
Scroll down to the UNITS item using the or RANGE key (UNITS: will be
flashing).
3.
Press ENTER to select setting (ENG or SCI will be flashing).
4.
Use the or key to display the desired units setting.
5.
Press ENTER.
6.
Press EXIT to return to normal display.
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1. The units setting can only be changed from the front panel (no remote
operation).
2. Scientific notation provides more resolution on small values than
engineering units.
