FAQs from Rohde & Schwarz

Correct measurement of resistance and current with the HMC8012


My HMC8012 shows slightly to high resistance / current when preparing for a measurement task. I tried to perform a zero calibration using the softkey "Null", but this did not work at all. Is there another way to perform this step?


In terms of zero calibration the hard key "NULL" should be used instead of the soft key.

Hard key NULL

The softkey allows to change the offset manually, but does not automatically use the current correction value as adjustment variable. Please prepare your measurement with the following steps:

1. Resistance

  • Enter the resistance measurement
  • Connect the measurement cables using COM and V-connectors
  • If you already know the target range, change the measurement range as desired
  • Short the ends of your cable and you will see the resistance measured:
Resistance measured
  • After pressing the [NULL] Button the display changes:
Display after having pressed NULL button
  • Your device is ready for the measurement now.

2. Current

  • Enter the DCI or ACI mode
  • Connect your measurement cables to the A and COM connector, but do not yet connect them to your PSU or DUT
  • You can see some misreading
DCI or ACI mode
  • After pressing the [NULL] Button the display changes:
After pressing the [NULL] Button
  • Now you are able to perform the desired measurement.

Prerequisites: HMC8012 with FW 1.400 or later, adequate warm up time (90 minutes) recommended.