<html><head></head><body><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;"><div>Hi All,</div><div>Today I did some extensive scrubber testing. Gamma has 3 axial scrubbers, one is Gamma'a original scrubber from 1971 with a smaller quiet fan. The next one is a home made scrubber made the same as Gamma's original, the third is a re-breather scrubber with a computer fan.</div><div>Interestingly after reading through some information Cliff sent me, I learned that the flow rate is critical. The only way I can change that is to fill the scrubber canister more or less. I started with 3\4 full canisters and a full re-breather canister and had a CO2 level of 950 PPM. With all three canisters full I had a CO2 level of 1133 PPM. So clearly the flow rate makes a big difference. </div><div>Now I understand why Gamma's original scrubber had such a big fan, in order for the canister to be full, the fan needs to be quite powerful.</div><div>I also have a true appreciation of how well the altimeter indicates how well the O2 level and CO2 level are monitored.</div><div>If the Altimeter was off zero even the tiniest bit, it correlated with the instruments perfectly. </div><div>Hank</div></div></body></html>