Field experience with ambient-level flame-photometric sulphur detectors.

Carbon dioxide exhaled by the operators produces increased levels of this gas inside the trailers used for housing monitoring equipment for use in the field. These levels can be high enough to produce serious calibration errors in flame photometric detectors used for measuring ambient concentrations of gaseous sulphur products. Quantitative measurement of the carbon dioxide interference in the sulphur emission is reported, as well as a method of estimating the extent of quenching agent pollution.