Need Help with GSR sensor

Hello

Im working in a experiment using a seedstudio Grove gsr v1.2, and I need to normalize the data for each subject to be able to compare them. For this, I recorded the baseline data at rest of electrodermal activity and the data recorded when presenting the stimulus proposed in the experiment.

I thought to subtract the baseline conductance data of each participant from all the data, in order to obtain only the activation peaks … the problem is that these sensors measure resistance and non-conductivity so I cannot subtract them because at certain times there would be negative data …

is there a way to convert this resistance data into conductance data? or some way to achieve what I want that I have not imagined?

im sorry if im posting this in the wrong place