Question
I'm using the HMC8012 and want to perform measurement of current and voltage on my DUT at the same time.
How do I have to connect the DUT and which settings must be performed?
HMC8012 - Display current and voltage measurement at the same time
Answer
The HMC8012 is able to display two measurement channels at the same time, but you should always keep in mind, that these measurements are performed sequential. This means among other things, that the described procedure is only valid for DC measurements.
1.) Connection
As voltage is always measured in parallel, while current needs seriel measurement, there is only one available way to connect the device as also stated in the HMC8012 Manual in chapter 6.5 ( Power Display / Ref. V04):
The more simplified representation:
For another example let's use a setup of a PSU in combination with three resistors in series connection. The task is to measure current and voltage for the middle resistor and also display the calculated power consumption. As I and U have the same ground reference, we now must accept a compromise. There is no way to connect the lines getting a positive value for U and I at the same time.
2.) Measurement (Ref. FW 1.40)
To be sure, we have the same device settings, let's start with a factory preset of the instrument:
[SAVE RECALL] (Device Settings) (Default settings)
The HMC8012 is in DCV mode now. We just have to change the second function to DCI:
(2nd Function) (Select)
Now use the rotating knob, select DCI and confirm by pressing this knob.
If the DUT is already connected, it might come to an OVER RANGE error. If the value is critical, the device will automatically switch to the 10A section.
By using (Range Up) or (Range down) the range can be manually adjusted.
It might be interesting to add the power measurement to the display in this case:
[MEAS] (Power)
3.) Result
