nitrox analyser

[Charlie99]

I have been looking at He analysis but the sensor poses a problem for the moment
Katharometers are very precise instruments ( and expensive ), hard to read and difficult to drive .Somehow i don't feel that that is what is used in the 900$ stuff out there. Real katharometers start at like 5K $ ....

does anyone have a picture of what is in the commercial helium analysers.
especically the sensor element interests me.
.

There used to be some good info at www.atomox.net . The website isn't active anymore, but you might be able to dig up some cached pages at the wayback machine or something.

His unit was being resold under a different name. I think, but am not certain, that Dive Rite was selling his unit.

He measures thermal conductivity. Basically a hot wire anemometer, but rather than assuming constant thermal conductivity and calculating out the velocity, he fed it with constant flow/velocity and calculated the thermal conductivity. Since helium has higher thermal conductivity, you can then calculate the fraction of He.

Charlie Allen