A technique for creating perfluorocarbon tracer (PFT) calibration curves for tracer gas studies

摘要

The use of sulfur hexafluoride (SF6) as a tracer gas for analyzing underground mine ventilation systems has been practiced for many years. As a result, the methods used to release, sample, and analyze SF6 are well accepted. Although improvements are still being made to enhance the analysis of this tracer gas, the technique remains basically the same. However, as the complexity and size of underground mine ventilation networks increase the capacity of a single gas to function as a convenient and rapid means of analysis diminishes. This problem arises from the need to allow SF6 to be completely cleared from a ventilation system before another test can be started. The utilization of multiple tracer gases can mitigate this problem by allowing for simultaneous releases in multiple underground locations thus facilitating a more comprehensive evaluation. Additionally, tracer gas tests can be executed in a consecutive manner without the risk of cross-contamination. Although multiple tracer gases have already been extensively used in the fields of heating, ventilation, and air conditioning (HVAC) and large-scale atmospheric monitoring, this technique has not been widely implemented in underground mine ventilation. This lack of use is partially due to the difficulty of releasing additional tracer gases. A well-documented alternative in HVAC studies to SF6 as tracer gas are perfluorocarbon tracers (PFT). However, many PFTs exist as volatile liquids at room temperature and pressure. This characteristic provides a challenge for quantification using gas chromatography (GC). This paper introduces a method for creating a GC calibration curve for gaseous perfluoromethylcyclohexane (PMCH) from its liquid form and details the experimental parameters used in the evaluation.