I am using a dual power supply model CPX200 from TTI in my school lab, and I am trying use it to supply 1.8V and 3.3V to a PCB, so I figured it was a good idea to check whether the ground of the dual port is coupled.
However, when I use multimeter DC voltage mode to measure the voltage difference between two ground terminal, it shows that the voltage difference is 0.3V and it starts decreasing slowly. I am having difficulties understanding this phenomenon.
So is the ground of dual power supply coupled? Why would my measurement decrease slowly? Thanks a lot.