Hello everyone,
first post on the board and a naive one at that : how can I use my recently acquired PCSGU250 to measure a DC tension ? It gives me a 50Hz sinusoid-ish signal even though the circuit’s input is a dedicated DC source.
In fact, I wanted to replace a multimeter by this USB oscilloscope and I’m starting to wonder if that was a good choice…
Thanks to you all !
The oscilloscope can be used to measure DC voltage too.
The accuracy is not as good as the accuracy of a multimeter.
[quote]It gives me a 50Hz sinusoid-ish signal even though the circuit’s input is a dedicated DC source.[/quote]Most probably the ground lead is not properly connected.
One other possibility is that the DC source has a high level of [color=#0040BF]ripple[/color] (unfiltered mains AC riding on the DC voltage), and/or you are inadvertently using AC coupling and there is a small AC component that is being displayed with a higher gain vertical scale.
Can you post some screen shots?
Maybe you used the “Autoset”.
When using the Autoset, the oscilloscope is set to AC coupling.
Oscilloscope searches the AC component. The oscilloscope settings are set properly to display the AC component on the screen.
Instead use the DC coupling and set the proper Volts/Div setting manually.
You may check the value of the ripple voltage and the value of the dc component of the voltage source you are using.
In the oscilloscope menu select: View -> Waveform Parameters.
In the Waveform Parameters dialog check both the check boxes for “DC Mean” and “AC RMS”.
You’ll see the DC and AC values of CH1 and CH2.