What companies make a portable gas detector for caving a.k.a. Spelunking?

Question

I need a list of companies and if anyone has suggestions that be great too.

Answer 1

I went spelunking near Lascaux, France (in search of artifacts) and used a gas analyzer from this company...

http://www.canarysense.com/index.html?s=...

I would shop around and purchase an analyzer specific to your application.

Answer 2

Lots of companies make detectors required by safety regulations for "Confined Space Entry"

Answer 3

DRAGER based in Pittsburgh about $800 for a full spectrum artificial canary.

Answer 4

Cavers don't need one. Walking through an abandoned mine is not caving, however. Carry a canary. I understand they work for birdseed.