How to calibrate extension cables so that they do not influence the test result?

When using extension leads, their ohmic resistance can be automatically subtracted from the test result. To do this, proceed as follows:

• Set ROFFSET from OFF to ON.
• "ROFFSET = 0.00 Ohm" is displayed in the footer.
• Select polarity or automatic polarity reversal.
• Short the end of the extended test lead with the second test probe of the tester.
• Trigger the measurement of the offset resistance with IDN.

The message ROFFSET x.xx Ohm now appears in the footer of the display, where x.xx corresponds to a value between 0.00 and 9.99 ohms. This value will now be subtracted from the actual measurement result for all subsequent RLO measurements, provided you have switched the ROFFSET ON/OFF soft key to ON.

ROFFSET must be determined again in the following cases.

• when switching between polarity types
• after switching from ON to OFF and back.

Note:

Use this function only when working with extension leads. When using different extension leads, the previously described procedure must always be repeated. If the difference between RLO+ and RLO- is greater than 10% during automatic pole reversal, no offset value is adopted. In the other case, the smaller value is stored as the offset value. The maximum offset is 9.99 Ohm. The offset can result in negative resistance values.