2nd stage trigger pull measurment

My trigger on my Sig Sauer ASP20 is like this. 1st stage, pretty long, which is fine with me, because it "hits" a definite wall/stop at the second stage. 2nd stage is very good/crisp and very little pull. I am using a Wheeler manual trigger pull gauge to check the trigger. As best as I can tell, it is about 1 ½ # to the second stage. And then it shows a little over 2# when it fires. If I pull it straight through it shows about 1# 9oz. My question is:

Is there a way to measure the second stage? I have tried resetting the gauge put to get the 2nd stage to fire it has to get the 1st stage done. It seems to me that the 2nd stage is only about 6-8 oz. from the 1st stage because it is light. Not complaining at all because it is serving me well but any thoughts?