Sorry about that
I meant .662 MeV of Gamma decay energy. Mistype. Also, I know that if the counter only picks up Gamma radiation, it won't be affected by the β- decay from the Cs-137, I just want to walk through all this logically before I stick it up on the rolling rack and start shooting...
So I have a bit of a story here. First of all, I work in my university's radiation safety department, where, among other things, I calibrate Geiger Counters. I also passed Modern Physics (Physics III), so I got some education on radioactive decay.
I have an old Counter from 1962, a...