The mathematical solution is complex.Actually @Tracy I had a ? So i was mixing for 38% for an upcoming dive. I filled all tanks to the required psi of O2. Plenty of time for them to cool.. actually double checked all tanks to make sure. Then I went to fill. I know that when I run my compressor I need to overshoot by some so they cool down to what I want. About 3-400psi. So 3500 get 3900, etc.
Now I went to test the next day and I've got 36% across the board.. the only thing I can figure is I should PP blend for 3900.. even though I know it will cool to 3500?
I'm a little stumped.. I know all systems are different, but there has to be a mathematical answer...yeah? Thoughts?
Control the fill rate carefully and room temp. note the difference. You should be able to dial it in from that data. Each tank will react differently.
10% overfill will only get you there with very slow fill rates.