Were going down fluorspar & t'owd mans lead mines, what gasses could we find & which monitor would be best for us, & do they detect bad air????????

All the best, Rope free......

Where? , and are there known / posted 'bad air warnings ?
Deal wi' that before splashing out on possibly unnecessary equipment.
O,G.

Don't think I've ever seen anyone carrying a gas detector other than a safety lamp on a (leisure) trip underground.

Don't think I've ever seen anyone carrying a gas detector other than a safety lamp on a (leisure) trip underground.

We use them all the time in some of the places we go to but presuming the original post refers to Pennine lead & fluorspar mines then we never would bother and we never encounter anyone else doing so.

http://cgi.ebay.co.uk/Gas-Detector-QRAE-II-4-gas-LEL-Oxy-CO-H2S-NEW-/180437040111?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item2a02e2bbef

(there was some scope for haggling the price)

Just checked back and I paid £276 for mine.

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We use them all the time in some of the places we go to but presuming the original post refers to Pennine lead & fluorspar mines then we never would bother and we never encounter anyone else doing so.

If you're just starting out a gas meter probably isn't a day 1 purchase (unless you're planning to spend a lot of time in coal or ironstone)

If its well trodden areas that every man and his dog has posted pictures of its fairly likely there are no problems with the air (although theres no harm in posting here and asking if you're unsure)

If you're starting to get well off the beaten track and going into uncharted territory then a gas meter is a very worthwhile investment.

Thanks for all your replies, they've cleared the air considerably.
I think we'll go for a safety lamp at the moment, Its only abbing into the unknown shafts that worries me.

Thanks again & all the best, Ropefree............

Buy a fag lighter with a piezo ignition (quid at most). If it lights you are ok if it doesn't start worrying.

Don't try this is potentially explosive environments.

I am scpetical about mine explorers and flame safety lamps. Whilst they do the job I strongly suspect that most people carry them for pose value.

About the only times a gas tester comes into its own is (a) when you are dropping unknown shafts and (b) when exploring ironstone or coal (not recommended) mines. On the downside you are looking at about £300 for a decent new single gas meter like a Crowcon Gasman

Thanks for all your replies, they've cleared the air considerably.
I think we'll go for a safety lamp at the moment, Its only abbing into the unknown shafts that worries me.

Thanks again & all the best, Ropefree............

Apologies if I was teaching my grandma to suck eggs.
I thought you were coming at this from the angle of new starter, not someone who's ready to ab unknown shafts.

I wouldn't recommend the gas meter I actually own, the GMI Visa, its far too susceptable to the occasional knock upsetting it and will start randomly showing errors on sensors at the drop of hat.

Thanks for all your replies, they've cleared the air considerably.
I think we'll go for a safety lamp at the moment, Its only abbing into the unknown shafts that worries me.

Thanks again & all the best, Ropefree............

Just one word of caution on this. The last fatality (that I know of anyway) was somebody abbing a shaft in a Scottish coal mine.

If you're suspicious you might encounter low O2 then its worth considering lowering the sensor down first, or suspending it below you. Last place you want to be if O2 dips to problem levels is somewhere you need to prussick out of.

Applicable to certain mine types more than others, but if you're concerned enough to want to use a sensor / safety lamp then it's worth erring on the side of caution.

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Interesting comment from Tamarmole about Davy Lamps.

I can't say I've ever noted anyone else using one. Plenty of gas meters though.

The thinner the fuel you use, the lower oxygen it registers before it goes out. I have measured mine in a bell jar of air/nitrogen and it went out on kerosene at 15% dead on (at 1020mb). I gather you can get down to about 14% using lighter fluid, however this is an expensive way of doing it.

Mine has a 8mm flat wick and I adjust it so it has a 2.5mm "point" of yellow flame. You can clearly see a flammables cap on it (which is more common than you might think) and it dims and lengthens around the 18% mark until it goes dimmer and then out. Then a quick lighter job will show you if you're under 13.5%! They do go out if you knock them though.

One point I noted about gas meters and flammables is that they are geared to "smell" methane. If you're looking at landfill gasses or fuel oil, etc, it'll confuse the meter.

You have to also bear in mind what happens with air pressure and use that information as well. The partial pressure of oxygen varies about 10% with the atmosphere. If you're in a depleted area, a weather front can take a chunk off your marginal situation and make it critical.

Our last meter was a QRAE and was very good indeed. A quick ebay will find you one.

Paraffin costs nothing and that in a Davy lamp, along with a lighter will see you in pretty much all the places a meter can take you.

A year or so ago, a few of us were in Wheal Jane (pyrite city) and climbed down into a section which was usually flooded and looking at the lack of footprints, we were the first in for a very long time. Cut a long story shorter, we climbed some stoping and felt like zombies. At no point did we smell H2S. I wondered if it was arsine (AsH3) as I had the symptoms of mild poisoning. (weak for days, struggled out of the shaft, etc). I gather it was likely to be H2S as there was very little As in the mine. Again, lack of water for ages and it built up in there.

I suppose our lot (about 3 years ago) were among the first I've bumped into among others (at a similar time) who were regularly taking meters out on trips. It resulted in a load of confused hysteria about numbers, rather than knowing the symptoms and the limits and acting in a sensible, methodical manner.

There is nothing like abbing down a shaft with a meter set at 17% for the first time, having no idea what 17% means and the meter suddenly, on the end of it's chord, flashing and sirens wailing. It is enough to make you **** yourself, regardless of the lack of oxygen! It's why I prefer a safety lamp. It doesn't give you the heebiejeebies as much.

I had a Neotronics blue and grey one which was as big as a playstation and a Crowcon one which had this fricking pump on it which went NAAAAAAAAAAAAAAAAAAAAAAAAA!!!!!! all the time.

The sensors on the neotronics were in a 4 pack and cost as much as the meter. Bearing in mind the O2 sensor "burns" slowly and eventually expires.... the QRAE is different and at least you get a few years out of it.....All the pissing around with calibration and expiring sensors. Take a lamp!

The little fella would be using a Drager pump got a couple from work never used them

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I think its difficult to find the boundary between over complicating matters and keeping common sense. Not everyone has a grip on chemistry.

The problem with Flame lamps is you need to keep an eye on them, and you need to know what your doing. I have very little clue about these devices, as I have not really used them, and do not own one,- this said, I have attended a course on their use some years ago, and still admit Im not in a position to rely on them. Perhaps it would be different if I used them every day as part of my job.

Gas meters just work (When Looked after and calibrated). Stuey makes a good point on levels, and a very good point on understanding variations etc.

Knowing what is safe, and unsafe is important, but I would say, knowing depreciation or increase of anything is worthwhile, so the situation can be monitored.

This is one of those hobbies that can kill you, even the well explored systems have their risks, the unknown have even more. These risks can be decreased with the right equipment and knowledge, and increased with the wrong equipment and stupidity. Go for the first one and stay alive. :thumbup:

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Not sure this helps much, but when the first portable sensors were marketed bought a Neotox detector, cost about £500 15 years ago!
The detector was used in the explorations in Scaleburn and measured the oxygen levels present. It is all written up.
The detector only had a shelf life of 9 months and at the exorbitant replacement cost we didn't.
The main problem with these fluorspar/lead mines is the increase in CO2 concentration.
If you start to feel you are knackered too quickly then it could be a lack of of oxygen.
Places we noticed it in was Haggs mine, parts of Guddamgill,
Barneycraig and Scraithole but there are probably others.
Incidentally I remember reading about a Welsh mine where an explorer passed out because he apparently went into an area in which the oxygen had been totally used up and only Nitrogen was left. As CO2 was only present in small amounts the body could not detect the lack of Oxgen!
Fortunately the explorer was dragged out by his mates and recovered.

Incidentally I remember reading about a Welsh mine where an explorer passed out because he apparently went into an area in which the oxygen had been totally used up and only Nitrogen was left. As CO2 was only present in small amounts the body could not detect the lack of Oxgen!
Fortunately the explorer was dragged out by his mates and recovered.

Interesting reading John. Any idea which mine that was?

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Interesting about the CO2 and lack of oxygen comparisons.

In my experience, low oxygen doesn't cause you to hyperventilate, you just feel slow/clumsy/woozy, whereas high CO2 makes you feel like you are suffocating.

I've had some good advice from some old cavers and slow is the way to go. Take it slowly and see how things are, if in doubt, slow down even more. You don't need a meter, just take it very carefully.... It sounds lame, but it makes lots of sense, if you take it steady, you'll be aware of the headache/jelly legs/etc, rather than steaming into some really critical stuff.

I've been in poor air to the extent that exertion results in cramp. I was sat in about 14% O2 whilst a mate prussicked out of a shaft. I found a nice piece of ore which I decided "dress" with my hammer, I got a "dead" forearm which came back to life with "a bit of waving around". The bottom line being that the overall effect was that movement seemed amplified. If you exerted yourself a bit, the affect was like you had done so much more. It just meant that you had to take things steady.

CO2 is different and neither your 4 gas meter or your Davy lamp can tell the difference between low O2 or High CO2 resulting in depleted oxygen. In a nutshell, CO2 makes your blood acid and the acidity results in your body trying to restore equilibrium by breathing out the cause of the acid. So, if you do lots of work, your CO2 in your blood goes up, you breath faster and you get rid of it. You aren't breathing because you need more oxygen, it's because you need to get rid of CO2. If you get into a CO2 atmosphere beyond about 4%, there is a nasty feedback cycle which establishes itself where your blood CO2 goes up, you breathe faster and your blood CO2 goes up and you breathe faster.....etc. If there is low oxygen, you run the risk of getting lactic acid induced cramp in whatever muscles you are using (namely your breathing muscles and your prussicking muscles) and it's not very nice.

I've heard tales from people who have been in very low oxygen, to the point that it seemed like a big joke, or they were that carefree they didn't realise the severity of their situation..... both of them got winched out.

It may be a bit sinister to say, but low oxygen doesn't seem like a bad way to die, it's not like you have an alarming feeling of suffocation like you get in high CO2.

It's a dangerous hobby and the best way is to know as much as possible about it. To say "You won't bump into X in a metal mine, or outside limestone country" is perhaps foolish.

Anyway, caveat emptor, etc, etc.

Thanks. A very thorough and thought-provoking analysis which I will re-read to ensure I've taken it all in. Bad air is something that I worry about (but I'm a born worrier anyway!).
A story from Ian Tyler's weighty tome on the mines of Cross Fell and the Western Pennines comes to mind of an attempt to reopen a coal level somewhere up the Tindale Fell way - a man was lowered into the level from above and was rendered instantly unconscious by the high CO2 level. Fortunately he was attached to a JCB and was brought up again quickly.
I'm sure your slow, steady and methodical approach is the key, with use of a flame lamp send down in advance when descending unknown winzes.

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I use paraffin in a Type 6 re-lighter but it needs to be opened and have a few drops of meths or lighter fluid applied to the wick to re-light.
This is a bit of a drag as one has to retreat to the last clear air area, not so much of a problem if just checking a shaft out.

If you use lighter fluid in a Type 6 it will re-light (if there's any Oxygen!)
It's not expensive for occasional use. You can also use "Colman fuel" but I had trouble with the re-lighter with this.

If you use lighter fluid in a Type 6 it will re-light (if there's any Oxygen!)
It's not expensive for occasional use. You can also use "Colman fuel" but I had trouble with the re-lighter with this.

I was using lighter fluid years ago when they had more regular use but now I have frequent requests from visitors for a demo, (are they real/do they work etc). Paraffin does not evaporate between demo's.;D
Having said that, one has been used UG (on paraffin) at least three times during the last four years.

...with use of a flame lamp send down in advance when descending unknown winzes.

I think you're missing the point there. The only thing a flame lamp can do is go out. A multi-gas detector will sound alarms at known levels. If it doesn't alarm it will record readings for your consideration.