Tektronix Keithley SourceMeter 2461, Calibration And Adjustment Manual

Page: 40 / 59

Section 4: Adjustment Model 2461 Calibration and Adjustment Manual
4-14 2461-905-01 Rev. A / February 2016
Current adjustment for the 4 A to 10 A ranges
When adjusting the 4 A to 10 A ranges using a shunt resistor, use the following formula to calculate
the current:
Current = Voltage / Resistance
Be sure to include shunt resistance uncertainty in the measurement uncertainty calculation when
using a current shunt.
1. With the source output off, connect the Model 2461 to the digital multimeter (DMM) using the
connection configuration in Connections for the 4 A to 10 A ranges (on page 2-5).
2. Turn on the Model 2461 source output.
If the Model 2461 is not already warmed up, allow it to warm up for at least one hour before
continuing to the next step.
3. On the DMM, select the DC current function.
4. Send the commands summarized in the following table in the order listed to initialize current
adjustment.
Current adjustment initialization commands
Command Description
*RST Restore instrument defaults.
:SOUR:FUNC CURR Select the source current mode.
:FUNC "CURR" Select the measure function.*
:CAL:UNL "KI002400" Unlock the calibration constants.
:ROUT:TERM <FRONT
or
REAR>
Select the front or rear-panel terminals that match your test
setup.
:OUTP:STAT ON Turn source output on.
* The measure range is coupled to the source range when simultaneously sourcing and measuring current,
so you do not need to set the measure range.
5. Adjust each current range using the procedure summarized in the following table. Do the
following for each range:

Send the
:SOURce:CURRent:RANGe
command to select the source and sense range to
adjust. For example, for the 4 A range, the command is:
:SOUR:CURR:RANG 4

Program the source to output the negative full-range value using the
:SOURce:CURRent
command. For example:
:SOUR:CURR -4

Measure the voltage across the shunt resistor, and then calculate the current.

Record the calculated current reading in the "Current calibration adjustment data" table in
Remote adjustment (on page 4-4).

Use the calculated current value as the parameter for the
:CALibration:ADJustment:SOURce
and
:CALibration:ADJustment:SENSe
commands. For example, a typical value for the 4 A range would be: