Nina,
I looked at LDAR for Furmanite sometime ago.
I suggest starting with METHOD 21, which will give you an easy method already written.

Depending on what results you want - anything from EXCEL, to a fully blown specialised software package is fine - I would suggest TRY BEFORE YOU BUY (Software licences are expensive).

Analysers come in various forms (PID & FID), I'll not explain here (the science bit) - just type it into google.

FID's are more accurate and can read higher PPM readings. But PID's are more robust.
I imagine PID's will get more and more accurate.

The best possible scenario is to do a survey with a small handheld PID, then any leaks you find measure accurately with a FID.

The most popular FID is the TVA 1000, but I find it rather heavy even in a back pack. Mine wasnt very accurate either. There is a better one called the MINIRAE 2000 which is handheld. Again - I imagine FID's will get more portable.

Try to use analysers that "comply with METHOD 21".

I'm a bit suspicious of the infra red one, which looks at the plant as a whole. You need to know which valve/flange/pump is leaking in order to repair it - and reduce emissions. But have a look at it.

If your company throws money at projects like this I would still be patient (try before you buy), and hire/loan/borrow a few and try them out.

The future developments for us? Instead of TAGGING valves/flanges etc, I am trying to convince Furmanite LOCALISED GPS is the way to go. We have problems with tags going missing.

LDAR is still something for the future, but as legislation tightens its good to already be set up and ahead of the rest.

I have a folder full of information here if you want it, but I found it all on the net. C