What is the safest way to ensure that a cave doesn't have a flammable/combustible gas, like methane or natural gas?
Is methane the only dangerous natural gas to watch for too? (I realize its the oxygen content that matters to breath, just don't want to go boom)
Since I know its odorless, and carbine lamps can ignite it and I've heard safety lamps reduce chance of igniting the air, or would gas meter be better?
I know very little about gas meters? I just know they have oxygen and co2 and methane meters.
The area is non active (extinct) volcano's and full of granite and limestone if that helps.
As a mountain climber I'm pretty sure we are talking about caves people just don't go into so there are no reports, nor can I find them on any maps.
Bats also live in the caves, so perhaps thats a good sign?

I know the signs of lack of oxygen, but am not aware of the effects that a flammable gas would have apart from going boom to a flame.
Any advice would be appreciated, we will be going back with torches, helmets, rope, glow sticks, PPE masks and what ever is recommended asap.

Have a read of this thread for starters:

http://ukcaving.com/board/index.php?topic=15212.0

I skim read that and mistakenly thought most of the information was based on co2 and passing out from lack of oxygen etc..
not natural gas (methane) going boom..
So sorry about that..

My worry is outside there are several red coloured flint type stones (stone that sparks from metal, not sure its composition is flint exactly) in that area, so it a climbing pick or metal torch dropped or steel calliper for example and found one of those stones, we all could be dead assuming it was an explosive gas.

Now having read it all, sorry... There was a few posts that helped alot..
One guy wrotes :
A standard confined spaces setup won't include CO2. You'll have O2, flammable, CO and H2S on these instruments.

Can someone point me to something that does measure O2, flammable, CO and H2S then please? I have no ideas where to shop online for stuff like this..
found this on ebay.. http://www.ebay.com/itm/New-Multi-gas-MS6310-Tester-Combustible-Gas-Detector-Sound-Light-Alarm-/221434618767?pt=LH_DefaultDomain_0&hash=item338e88238f
anyone used anything like this, definitely cheap, suppose I could test it with my gas camping stove...

Thanks in advance

http://www.gasmonitor-point.co.uk do a range of products from reliable manufacturers but they cost in the hundreds of pounds rather than the tens. Money worth paying if they save your life, in my view.

I think if you were more forthcoming about what you are trying to do and where then we might be able to provide some more useful advice.

It's also worth knowing that as well as purchasing gas monitors, they will often need recalibration at certain intervals and this also costs an appreciable amount.

What area are you talking about?

Canaries!

Potentially the answer to both "where are you going?" and "what should I use to detect gas".

What area are you talking about?

Well Brocklebank if he is a old NPC member you won't get an answer.

Cigarette lighter is a very cheap way of detecting high CO2, bit iffy with others I suspect though.

Bottlebank said:

Cigarette lighter is a very cheap way of detecting high CO2, bit iffy with others I suspect though.

Click to expand...

A bit too effective for detecting Methane...

paul said:

Bottlebank said:

Cigarette lighter is a very cheap way of detecting high CO2, bit iffy with others I suspect though.

Click to expand...

A bit too effective for detecting Methane...

Click to expand...

Very good at clearing methane, though ...

The old miner's lamps (Davy lamps) were designed to be safe in a flammable atmosphere, and also indicated the presence of flammable gases.

Not enough lumens for today's cavers though, I suppose.