The SF 6 Tracer Technique: Methane Measurement From Ruminants

The purpose of this document is to describe in detail the sulfur hexafluoride (SF6) tracer technique. Included within are instructions to construct and use the equipment needed to make accurate measurements of methane emissions from ruminants. However, as with any technique, improvements and modifications are needed and will occur with continued use. As long as the basic principles behind this technique are followed, modifications to improve ease of use will not compromise measurements. The list of sources and part numbers are included only to help users understand what is needed and not to imply that other sources are not acceptable. The authors of this document are very interested to hear of the successes, problems and solutions that users encounter with the technique. This document is divided into four sections: Section 1: This section is intended to introduce the reader to the SF6 technique and to give background information as to its development. Section 2: Specific instructions regarding construction and assembly of the different parts needed to measure methane are included in Section 2. Section 3: An example sampling sequence, a calculations summary and a Quality Assurance document are included in this section. Section 4: Appendices include a troubleshooting guide, assembly directions, parts list and the steps for preparing an SF6 permeation tube.