Draughtproofing

[AndyF]

Surely there are some really smelly things like isocyanates (?) that a sniffer could detect?

Quite tricky. I used to work with some equipment that used Ion Mobility Spectroscopy to detect explosives vapour.

Problem is it just isn't very good, you need quite high doses to get reliability, and false detection is common.

I suspect a draught would dilute anything smelly too much to be of use.

 

[emgee]

My memory might not be what it was.

... but Nostalgia remains the same!

No definitely not what it used to be.


Well someone had to say it.

 

[Dave H]

I think there has been some work on temperature variation ...

There's usually plenty of hot air expelled by some cavers - not always from the end the Butcome ravages :wink:

 

[gus horsley]

The intensity of draughts also depends on the size of the passage. How often have you dug a "howling gale" only to find it closes down to zilch after a few feet. I remember digging a draughting crawl in Greenbridge Cave for a total of 120ft to a point where the draught disappeared completely and the air became decidedly stale. And it wasn't a seasonal variation, like you get in some systems.