Just to compare all 4 cylinders and verify they do not differ too much.
I can check later on if changed which can show issues like leaking valves or worse if the drop is high.
This was one of the reasons I understood to change head asap when my old had suddenly dropped around 20 PSI on 2-3, 1,4 as before.
I tested different cams before and noted the pressures. This verified the cams overlaps and how it affected compression.
DP315 with different lash changed compression rather much.
And yes, it worked better with the 0.12" recommended lash, compression difference compared to less than half lash used by many other cams.
Interesting to see relative measurements.
With same tool I can compare the change when replacing cam, head and/or pistons.
Compare one build with another.
My K2 had around 140-150PSI with stock type pistons. 30 more with different pistons, everything else same.
Now I know how this build is working. If I should change head, I do not want to see lower values
Maybe not too much higher either, forcing me to use thicker gasket, increase the squish or even worse, use another cam with more overlap when this cam work fine.
Very useful simple tool, note the compression.