5-11
IM 2558A-01EN
Voltage and Current Generation
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App
Index
5.7 Finely Adjusting the Output (Deviation and
Preset)
Procedure
Deviation
Turn the
deviation
dial to set the value. The DEVIATION display shows the value. Turn the
deviation dial right to decrease the deviation and increase the output.
Example of setting –1.50%
The specified deviation
Set the hundredths digit.
Set the tenths digit.
Preset
Flip the
PRESET
switch up or down to select a preset. The selected preset indicator illuminates,
and the deviation display shows the value.
Example of setting -2.00%
Select a preset.
Presets
Explanation
Deviation
When you calibrate a meter using the 2558A, use the deviation dials to read the deviation of the
target meter (the error between a scale value and needle). Use the main setting and the output divider
feature to output the meter scale values (nominal values) and use the deviation dials to align the meter
needle to the scale values.
If you turn a dial to the right and set a negative value, the 2558A outputs a value that is larger by the
main setting value × the deviation. A negative deviation means that the meter needle is indicating a
value less than the 2558A output.
Example If the main setting is 100 V, the divider value is 5/10, and the deviation is –1%, you will
obtain the following result.
Deviation = 100 × 0.01 = 1 V
Because the divider value is 5/10, the output value is 50 V + the deviation (1 V), which is 51 V.
• If you change the main setting or the divider value, the value set with the deviation dial will be
cleared.
• If the preset is set to 0%, 2%, or 5% and you change the main setting or the denominator m of the
output divider, the deviation will be cleared. If you change the numerator n, the deviation is set
based on the preset setting.
• You cannot control this setting while a sweep is in progress.
• If the output range is exceeded, the display blinks.
