FAQs from Rohde & Schwarz

How to startup your HM8118 using a specific calibration


I perform the open and short calibration on my HM8118 and it works fine. After I restart the device, the calibration data is gone.

Is there a way to keep the calibration after switching of the unit?


The open/short calibration data of the HM8118 can be easily saved using the Store / Recall function of the device.
It is important to use memory "0" in this case.

  • Calibrate your device using the specific settings (e.g. change frequency to 2kHz)
  • press [RECALL] two times, so that the display shows "Store" (FW. 1.57)
  • to choose memory "0" press [G-B]

You can easily check this function if you use a low value resistor instead of e real short while performing the short calibration.

The R-Q measurement will display close to 0 Ohm now. If you restart the device using the Power switch on the front panel, the instrument will lose the calibration and still show the real resistance.
When you now do the same, but store the calibration to Memory "0" in addition, your HM8118 will then show close to 0 Ohm after the restart.

E.g. 3,3 or 0,28 Ohm have been approved while writing this note. Values higher than 10 Ohms including test

leads and contact resistance will end up to a calibration error "Z > 15 Ohm or R > 10 Ohm - press any key to exit"