Good Afternoon All,
It is likely that I will soon be exploring places for which having a Gas Monitor would be sensible. They are Ironstone, so I believe the general problem is oxidation of the iron depleting the oxygen levels rather than high levels of other gases.

What Monitors do people typically use?

Thanks,

Chris.

MSA Altair 4.

https://gb.msasafety.com/Portable-Gas-Detection/Multi-Gas/ALTAIR ®-4X-Multigas-Detector/p/000080001600001022

Not the cheapest but far and away the best on the market at the moment and has been for years. General durability, waterproofedness, user-friendliness, programmability and downloadability they are miles ahead of the MicroClips, Protoges and BWs.
With the MSA you can specify which sensors you require. If O2 depletion is your biggest worry then you can ask them to delete one of the other sensors and fit a second O2 sensor for redundancy. Typically I would think that the carbon monoxide sensor you can live without in recreational mine exploring unless you plan on running a genny or something underground. And if your going to do that you don't need a gas monitor to tell you that you're in trouble! :lol:

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I picked one up second hand with its charging cradle for £80 on fleabay. As I expected, the O2 sensor was shot but a replacement cost £30. It'll still need calibrating at some point (another £40-£50) but I'm not going underground at present so for now it can live in a ziplock bag with an oxygen scavenger for company . As Sinker says, they're solid bits of kit...

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Bit of a side issue, but there have been two Carbon Monoxide issues that I'm aware of in lead mines - one was at Long Rake Mine near Bradwell in 2009 I think, where two visitors came out feeling very ill and testing showed high levels in their blood. It was never demonstrably proven that the gas was actually in the mine though, and the place is still closed at the landowner's request as a result. I've still never been :(

The other was at a mine shaft on private farmland near Elton a few years ago that had swallowed a cow, and an initial test with a lowered Altair showed very high levels of CO. A return visit was made a week later with a shaft-inspection robot with a gas monitor - I was actually present at that one - and the readings this time were even higher - deadly in fact, so we were unable to even descend a little way. Both monitors were well within calibration and worked fine, so we still have no idea what was causing the Carbon Monoxide. On a limestone plateau on farmland I can't think of anything - there is lava down there, but not much else unusual that's 'natural'. The farmer said he'd lit some newspaper and dropped it on his first visit. My instinct is that whatever it was causing the huge amount, it was below the cow, which was jammed about 30m down at the time, and that whatever it was, it probably shouldn't have been down there.

Regarding oxygen monitors and calibration. There are two main systems in use depending on how your monitor is configured.
One needs external test gas calibration and will set at the correct zero (20.9%) whether underground in bad air or not, based on internal settings. the other calibrates itself at start-up from the atmosphere, again, 20.9%.
You need to know what your meter is set to as if you don't turn it on before going underground, the second config. means you will be zeroing in bad air and getting a false reading.
The first config. type is correct even when turned on underground.
As long as you have a good battery that will stand working for all your trip, the second config. is best for amateurs. It means you don't need to spend money getting your meter calibrated every 6 months. The other gases, once calibrated, seem to last a very long time before any obvious calibration drift. In any case, it is extremely rare to get the other gases anyway.

Thanks for the input all. I shall look at the Altair 4x and see what the options are.

Chris.

COMRU use both Honeywell and Crowcon 4 gas monitors.

Just a heads up in terms of rescue. Their protocols say that the team should exit the area if the gas detector alarms regardless of where the casualty is, regroup and make decisions based on that. They use industry standards as do all the underground rescue teams.

The impact of this, for all those 'hard' mine explorers who say they're OK below 15% Oxy. etc. is that it may take much longer for the rescue team to sort out what to do and get to them.

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Just a heads up in terms of rescue. Their protocols say that the team should exit the area if the gas detector alarms....

Interesting; what gases are monitored for?

I imagine Oxygen, Hydrogen Sulphide and Methane?
And what levels are the alarms set at?

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The impact of this, for all those 'hard' mine explorers who say they're OK below 15% Oxy. etc. is that it may take much longer for the rescue team to sort out what to do and get to them.

Discussions among various friends, including COMRU members has led us to the painful conclusion that while you may be OK personally with levels way below industry standards, if you end up in trouble in the lower oxygen levels then unless the injury is relatively slight and you are well equipped with food drink and a survival blanket, etc then it is much more likely to be a recovery than a rescue. If you have ended up in an area where you have passed out from limited or excessive gas levels then definitely a body bag job, if at all.
It makes you think...

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Whats the consesus on here about the BW Microclip x3?

I've decided to get myself a sensor as theres a couple of places I'd like to see which have had some reports of bad air. I don't really need anything fancy, just something reliable that will keep me alive. Looking at the Altair the monitors themselves fairly reasonably priced but the other bits like the chargers seem to be priced very high for some reason.

It will only be used for walkarounds (No SRT or digging)

Whats the consesus on here about the BW Microclip x3?

…..something reliable that will keep me alive. Looking at the Altair the monitors themselves fairly reasonably priced but the other bits like the chargers seem to be priced very high for some reason.

It will only be used for walkarounds (No SRT or digging)

If you want it to be reliable for ever then go for the Altair.
If you want to worry about it when a few drips of water drop on it or it gets slightly damp in your rucksack then go for the BW.
There's a reason the Altairs are a bit more pricey. When you study the build quality of both then the reason is clear.
I've used the SAME one every day for 5 years without a single issue. And another one previously for 6 years with one failed O2 sensor in that time. I've seen a BW dropped from shoulder height onto a concrete floor and the case split open. Write off.

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I feel that I need to comment and draw attention to the British Cave Rescue Council guidelines, published in October. While these contain strong recommendations not to change the alarm settings for carbon monoxide, hydrogen sulphide and methane (LEL), they also suggest that cave rescue teams become familiar with what is usual in their areas. Many members of cave rescue teams, who also explore mines will frequently enter areas where the oxygen levels are below the default alarm settings of commercial gas monitors. To cite a couple of common locations would be Sir Francis Level, Swaledale and the Horse Gin in Rampgill.

Carbon monoxide is clearly one of the gases to be particularly cautious about but it should not be in a lead mine and I think serious questions and investigations are warranted when something so unusual occurs.

I suspect that one of these high carbon monoxide levels might be due to the presence of a cow (high methane), limited space (limited oxygen) and the addition of a burning newspaper (i.e. partial burning/oxidation of the methane). Investigation after a significant time gap would be sensible. If there really is high carbon monoxide, its source should really be understood in case there are wider implications.

At the time, there were suggestions that the Long Rake incident was related to fumes from a near-by quarry.

One thing I shall add is .

Altair power !!! :thumbsup:

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You could look out for a second-hand Altair on Ebay with charger, they sometimes come up being sold as untested or not working, probably because the oxygen sensor has expired. Replacement sensors aren't massively expensive.

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I payed £240 with charger new calibration with certificate.

Give you a idea

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Loads of them on eBay usually.

Genuine ones seem to start at around £150. :thumbup:

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Whats the consesus on here about the BW Microclip x3?

I've decided to get myself a sensor as theres a couple of places I'd like to see which have had some reports of bad air. I don't really need anything fancy, just something reliable that will keep me alive. Looking at the Altair the monitors themselves fairly reasonably priced but the other bits like the chargers seem to be priced very high for some reason.

It will only be used for walkarounds (No SRT or digging)

I have the Microclip X3 and think it is excellent. Cave rescue use them too, along with the rather more expensive 5 gas version. We have not broken any yet! Mine has done wet, dirty and tight with no signs of damage. Small, easy to use and I have access to the calibration kit already.
I had a Scott Safety Protégé for a while. Died after 1 year. Not recommended.

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I would also disagree with the statement about the BW being unreliable.

I've been using a Microclip for the best part of 4 years now, its never had an issues despite getting wet/damp/muddy on most trips.

Also hasn't needed a new oxygen sensor yet, which must be some sort of record.

I guess i was extremely lucky then. I managed to get an Altair x4 from ebay for £100; it had the charger and nearly a full cali on it.

Seller had a zero sales rating though so it was a massive punt on my part but it turned out reet.

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