RE:Does anybody know the technology used by themI run a high end analytical lab. Although, I do not have any insight into the instrumentation that they are using, it is likely they are likely using is a GCMS or perhaps just a specialized mass spectrometer. Even though you can isolate a signal for Helium on a GC, you can not distinuish He4 from He3 unless you have a MS. Most MS systems do not normally look at low masses below 10 amu, but you can determine this using a properly tuned system. I expect that they might have a simple GCMS or even GC on site to provide a rough estimate of Helium and other gasses present then sent a sample off for accurate HE3/He4 ratio's. At least that is how I would do it. Again, pure speculation.