I am trying to measure the voltage between 2 points using an oscilloscope and a multimeter.
I am getting a difference when I measure the voltage using an oscilloscope and using a multimeter in the order of 10mV and in some cases 100mV. I am using a ground clip when I use the oscilloscope as shown below. What might be the reason for the difference for this?
Question 2 :
Suppose I measure voltage between two points (both of which are not ground - differential voltage) using an oscilloscope, is using differential voltage probe the only way to measure the voltage between those two points (both are not ground,) or can I use a single probe with the ground clip (shown below) to measure the voltage between those two points (both are not ground) - Is it safe?
I perform this above test with 2 power supplies : Using a bench power supply to the power the board and in another case, I use a 12V lead acid battery to power the board.
The oscilloscope is connected to earth ground and the power supply through which the board is powered is also earth grounded. In another case, I am powering the board using a 12V lead acid battery alone, and the oscilloscope will be connected to earth ground.)