Adjusting a 1000 Series Remotely - DC Voltage and Current

Step 1 : 

Set the range that you wish to adjust

Step 2 : 

Enter calibration mode by sending the command a1

Step 3 : 

Read back the calibration factors for the range

"CALIBRATION:PRINT" will respond with the calibration factors for the range, separated by carriage return line feeds in the following order

POSITIVE FACTOR<CR><LF>
NEGATIVE FACTOR<CR><LF>
ZERO POSITIVE FACTOR<CR><LF>
ZERO NEGATIVE FACTOR<CR><LF>
*0<CR><LF>

The *0 indicates the end of the response.

An example can be found below :

279486223
27947905
3832
3892
*0

DC Ranges use the Positive Factor, Negative Factor, Zero Positive Factor and Zero Negative Factor

Step 4 : Adjusting the ZERO factor

Note : The 1000 Series is different from the 3000A / 4000 and 9000A in that there

Calculate the difference between the measured output and the nominal setting, and then convert to base units (i.e. Volts or Amps)

Reading - Nominal = Difference

I.e.

0.001mV - 0.000mV = 0.001mV = 0.000,001V

Voltage

          100mV  ZBit = 0.000,000,001  

          1V         ZBit = 0.000,000,01   

          10V       ZBit = 0.000,000,1  

          100V     ZBit = 0.000,001 

          1000V   ZBit = 0.000,01

Current

         100uA:      ZBit = 0.000,000,000,001

          1mA:        ZBit = 0.000,000,000,01

          10mA       ZBit = 0.000,000,000,1

          100mA     ZBit = 0.000,000,001

          1A            ZBit = 0.000,000,01

          10A          ZBit = 0.000,000,1

The new Zero factor is then calculated as below

Old Zero Factor - ((Difference / Zbit) * -1)

Worked example

3832 - ((0.000,001 / 0.000,000,001) * -1) = 4832

After performing the calculation, send the new calibration factor back to the unit with the following command :

"Z" followed by the new factor. The calibrator knows which Zero to update based on the set value

Step 5 : Full-Scale Adjustment

Figure out the percentage error.

((Reading - Nominal) / Reading) * 100

i.e.

((1.005 - 1.000) / 1.005) * 100 = 0.49751

Positive Factor - (Positive Factor * Percentage Error) / 100

Do the same for the NEGATIVE factor if required.

Valid factors are TYPICALLY between 241591911 and 295279001; if the calculation is outside of these parameters, there is an error in the measurement or readback.

Note - the calibration factor is always positive

Step 6 : Storing Calibration

Send the new factor back to the calibrator.

If a POSITIVE factor, send the command "P" + the new factor
If a NEGATIVE factor, send the command "N" + the new factor

Step 7 :

Re-run the test to confirm the change has been applied

Step 8 :

Save calibration factors

Note - you MUST save calibration factors before changing range or turning the unit off. Changing range before saving the calibration factor will result in the adjustment being lost

Send the command "a2" to store the new calibration