Gas monitoring instruments and systems for fumigation
Sea cargo containers and wooden packing materials are fumigated to control the spreading of pest animals and micro-organisms. Fumigant gases are toxic and measurements are carried out as a health and safety precaution. Measurements are required by e.g. customs inspectors prior to opening containers, making the shipping companies responsible for carrying out measurements. Products shipped in containers may release VOCs from e.g. solvents and glues used in manufacturing process. The concentrations of vapors may be significant in the confined space of the container. While most containers originate in China and Southeast Asia, cargo container measurements are done in ports across the world, as the same gases are encountered in all ports.
The battery-powered, backpack-size Gasmet™ DX4040 Multicomponent FTIR Gas Analyzer records infrared spectra at 10 scans/second and is capable of sub-ppm detection. The DX4040 requires no span gas calibrations and only a short zero calibration in the field before starting the measurements. The analyzer is controlled by a standard laptop computer or a rugged handheld PDA. The Calcmet™ software for measurement and analysis is used to control the analyzer, and performs the analysis of the measurement data for generation of qualitative and quantitative information on the sample gas composition.
The DX4040 performs simultaneous analysis of up to 50 gases with compensation for cross-interference effects. The FTIR (Fourier Transform Infra-Red) measurement principle allows determination inorganic and organic substances regardless of their molecular weight. The gas library is configured to include all common fumigants and a wide range of substances released from the cargo for correction of cross-interference effects. The results produced by Calcmet software can be traced back to the original infrared spectra of the samples, and a built-in QA/QC routine ensures reliable results.