[voxmpg]

Hi,
     I am doing a research project on analyzing medical gases and I was wondering if anyone has any ideas on how to mix gases like Carbon Dioxide, Nitrous Oxide, and Oxygen to known amounts. Basically, the idea is to test the accuracy of sensors by mixing the gases and comparing the known concentrations of each with the readout given by the sensor. For instance, I'd like to take a tank of oxygen and carbon dioxide and make a gas mix of 50% O2 and 50% CO2, then run it through the sensor and ideally get a read out of 50% for each gas. If anyone has any ideas let me know. Thanks a lot.

[Borek]

Do you have to mix them at the time of measurement, or can you prepare the mixture earlier?

My first idea was to use rotameters, but I doubt they will be accurate enough.

[voxmpg]

Do you have to mix them at the time of measurement, or can you prepare the mixture earlier?

My first idea was to use rotameters, but I doubt they will be accurate enough.

No the mixture can be made ahead of time and then the entire mixture can be run through the sensing machine for analyzing.

[Borek]

Can't you mix them over water? Using inverted cylinder or something? This way it will be easy to measure the volumes when mixing.