Gas smell

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Discussion

Howitzer

Original Poster:

2,835 posts

217 months

Wednesday 7th October 2020
quotequote all
Hello,

I’m working on a project where a complaint of gas has been made and I want to show that this is not the case.

Essentially we have 5 areas that could possibly be a cause of a gas leak. I want to test these areas every hour to show we do not have a leak.

My question is, what kind of PPM would be noticeable by the human nose ? I’ve tested for gas leaks in enclosed places before but have no idea on the limitations of the human nose for domestic gas. There is no point me testing at 40PPM if the nose can smell
Down to 10 for example.

Any help would be much appreciated. I’ve done some googling but it just references exposure levels.

Dave!

Beati Dogu

8,898 posts

140 months

Thursday 8th October 2020
quotequote all
They add Mercaptan to gas to give it a more distinctive odor, so you'll probably find what you're after by searching for that. Our noses are much more sensitive to Mercaptan than to methane itself, which is of course why it's added.

E.g.:

[Unlike methane], "the mercaptan used to add an odor to the natural gas is heavier than air and can be detected by the human nose at about 1 ppb (part per billion) in air."


https://www.levitt-safety.com/blog/natural-gas-det...

https://en.wikipedia.org/wiki/Methanethiol

Howitzer

Original Poster:

2,835 posts

217 months

Thursday 8th October 2020
quotequote all
That’s excellent thanks.

So from that I’ll have to try and check each flange for the source of a possible leak as apposed to hold the detector in that area.

A bit more work but should at least get some worthwhile results.

Dave!