Hello everyone, I have recently owned a gmc 600+ and today I tested the tiles in my house. I understand that the radioactivity is almost three times that of the fund. On some occasions I have barely exceeded 150 bpm. Is this the same for you? what do you think?
The result is quite possible. What you see is probably the Potassium content, aka K40, of the tiles.
As K40 is a strong beta emitter (and minor gamma emitter), you can further discriminate your measurements by putting a stack of paper, like 10 sheets of copy paper, between tiles and counter. You should see a significant drop of counts.