My project just bought UGGA LGR(TM), we are going to use in tropical peatlands. But it seems the distributor could not provide a procedure for GHGs measurement and also the calculation?.
The use of the LGR is quite easy. It depends on what you're planning to measure, but normally we use it together with a floating chamber (for fluxes) or an equilibrator (for water concentrations). It works in a closed system, so both the in and the out of either the chamber or the equilibrator goes in the LGR. It reads concentrations every second if you want to, which make measurements very accurate. You can also develop and manual injection system, to use it as a GC, injecting samples in the field. It is really a life changer if you're used to a lab GC. We can talk more if you like, and I can share some of my experiences in the Amazon with you.
Thank you very much Pedro for your answer. How do you calculate the flux rate?. for example If we want to know the rate in ppm/minute/meter square. Is there any correction should be applied to measure the flux rate?.
I'd love to explore more, so if you don't mind we can discuss further.
this is my email [email protected] and Skype taryono.darusman
thanks
Taryono, the flux rate is calculate as the slope of the regression of the concentration in the chamber vs time of deployment. You will have to consider the volume and area of your floating chamber. The formula would be F = (s(v/R xTair xA))x t
where V is the volume of chamber (m3), R is the universal gas constant (8.205 x 10ˆ5 m3. atmˆ-1. Kˆ-1. mol ˆ-1), Tair is the temperature inside the chamber (in Kelvin - if you cant measure that use the water temperature at time of measurement), A is the chamber area (m2), and t is the conversion factor from seconds to day, and to umol.
It's actually easier than it seems. You can send me an email if you have further questions. [email protected]