App-2
IM 2558A-01EN
Appendix 2 Example of Using the 2558A to Calibrate
an Analog Meter
Output Divider
When an analog meter is calibrated, the 2558A is used to output different voltages or currents so that
the meter needle can be adjusted to match the minimum and maximum scale marks and the scale
marks in between. The 2558A enables you to set the voltage or current output for the maximum scale
mark with the main setting and calibrate the different points of the meter by dividing the output, rather
than changing the main setting. See sections 2.3 and 5.5.
Ammeter
0A
Main setting = 10 A
n = 0
m = 4
Ammeter
5A
n = 2
m = 4
Divider value: 0/4
Divider value: 2/4
Presets
There are two ways to calibrate an analog meter. One is to calibrate from the minimum value up,
and the other is to calibrate from the maximum value down. In either case, it is necessary to keep
the needle from exceeding the next calibration position when the meter needle is move to the next
calibration point. The 2558A enables you to set a preset to make the meter needle point to a position
short of the accurate scale position of the next calibration point when the voltage or current is output.
See sections 2.4 and 5.7.
Ammeter
4.5 A
Main setting = 10 A
Use the output divider to
move the meter needle up.
Preset (5%)
Indicates a point that is
short of the calibration point
by the preset amount
Example when calibrating
in increasing order
