Many thanks for the link.
I have already found a UK based company that appear to sell a device and tried to buy one, but in our nanny state it seems they need to know the colour of my underpants and my great great grandmonther's second cousin's cat's name before they will even talk to me... I presume one can get seriously injured using a handheld hydrogen meter so they need to take porecautions who they sell it to. Or maybe the device can be used as a weapon of mass destruction.
More seriously I was also hoping for something less expensive if at all possible. As I am typing this message I am also looking for hydrogen sensors maybe we can put something together and make something that is cheaper than $2,000 and does not require NSA clearance!