Mixed gasses

[Steve Walker]

Didn't Wheeler Dealers make up battery powered LED replacements to fit in place of the carbide lamps in a Daraqs headlamps?

SteveW

[Thomas Prufer]

"Petzl Ariane", a modern carbide haedlamp.

Possibly discontinued, but sometimes available used.

Thomas Prufer

[harry]

Yes it's strange. We used to buy it as schoolkids to mess around with. But there were no acetylene lamps around at that time so why they had any is a mystery.

[harry]

Yes, that's the one that was for sale in Halfords.

[Brian Reay]

Interesting. I've only seen such lamps a few times and not noticed that. I wonder if, for cavers etc, they produce better quality (pure) Calcium Carbide as H2S is dangerous. I believe it was used in WW1.

[Matthias Czech]

Am 17.12.2019 um 11:23 schrieb harry: [carbide]

It was used for killing moles.

[harry]

It's also flammable and so would be burned up.

[Chris Hogg]

The acetylene from a carbide lamp always had a very characteristic slightly sweetish smell, and no, AFAIK the carbide wasn't particularly pure. H2S is almost as poisonous as cyanide gas, or so I was taught at school, but when generated from a carbide lamp it's immediately burnt, so never builds up to anywhere near a lethal concentration. Nor do I think it would do even if unburnt unless for an extended period in a very confined space. It's not as though you'd drop dead from the slightest whiff of H2S, any more that you'd drop dead from the slightest whiff of HCN (I have smelt both, and I'm still here!).

[Robin]

I think some people may be assuming caves are prone to be short of air circulation. That was not my experience in the few I explored - not even when a podgy like me was plugging a squeeze.

[Steve Walker]

ISTR that if you can smell it, it is okay, when the concentration is higher, the effect stops you smelling it. At least that is what we were told in "O"-level chemistry - so it could be completely wrong!

SteveW