Simple, low-cost flow controllers for time averaged atmospheric sampling and other applications.

GERE J. I.; WILLIAMS K. E.; JULIARENA P.; GRATTON R.

Palmerston North

Workshop; Technical Guidelines on implementation of the SF6 tracer technique for determining methane emissions from ruminant livestock: An outline and discussion; 2011

Global Research Alliance

Usually, sampling sets for the SF6 tracer technique accumulate air up to 0.5 bar within 1.5 L PVC canisters in 12 or 24 hours. Even though that in the first experiment in Argentinean cattle production (Bárbaro et al, 2008) was replicated the typical use of the SF6 tracer technique, was necessary incorporate several changes to improve the performance in the samples collected, for instance, the use of small vessels. The use of small vessels requires air inflow regulators with conductance of the order of 0.35 ml/min for a pressure difference of 1 bar. It is expensive and not practical to use capillary tubes as usual in single-day sampling (of course, a short tube stretch may be easily squashed).