Test for hydrogen

How about the lighter test? If you see a fireball then there was some hydrogen there. What is this in reference to?

You really are a dopey sod, the pop test is when you put a lit splint in a test tube full of hydrogen. It makes a loud pop. How different is your lighter test?

Mass spectroscopy? (H2 is the lightest molecule.) It's easy if you have a mass spectrometer.

Or if you have some pure gas and your question is whether that gas is hydrogen or not, you could fill it into a balloon and see if it flies.

It's always nice to see an answer from someone who has a clue. Is there anyway other than using a mass spectrometer? How do you know your balloon isn't full of helium?

You could measure the force with which the balloon pulls up, then subtract the force with which the same ballon pulls down when filled with the same volume of air. From that, you can calculate the mass density of the gas that's in the balloon. Finally, you compare that to what you expect based on the known mass densities of Helium and Hydrogen. (Helium is denser than Hydrogen but less dense than air.)

Well I'm convinced, but I didn't ask the question.

There are low cost explosive meters that can do it for you. Example: http://www.teledyne-ai.com/manuals/man_2240.pdf If you are doing something that generates significant quantities of hydrogen, be careful. 4% H2 in air is explosive so you might do the pop test by accident.