gasmet_application_note_container_measurements
6Pages

GasmetTM FTIR application note Container Fumigation KEY WORDS        Container Fumigation Fourier Transform Infrared (FTIR) Fumigant Ventilation Pest animals Library Search Tool DX4040 Portable FTIR Gas Analyzer Calcmet 4040 Professional Analytical software package OVERVIEW Sea cargo containers often contain hazardous levels of gases and vapors which are dangerous for the people working in inspection, loading and unloading. These gases are either fumigants or are arising from the packaging materials and goods. Some of the containers and wooden packaging materials may contain pest animals and micro-organisms, so they need to be fumigated in order to avoid the spreading of invasive species and diseases. After fumigation the containers should be labeled with proper warning signs, (Figure 1) so that they are ventilated before opening. However, absence of marking cannot be taken to mean fumigants are not present. Containers marked as having been ventilated after fumigation may also contain fumigants that were absorbed by the cargo and released during transit. Some products shipped in containers may release VOCs, for example, from solvents and glues used in manufacturing processes, in which case the concentrations of toxic gases may increase to significantly high levels in the confined space of the container. Generally, it is necessary Figure 1. Warning sign on container during fumigation. Copyright Gasmet Technologies

for measurements to be taken by customs inspectors, as a health and safety precaution. Usually, customs staff select the containers to be measured based on factors such as the country of origin of the container, the products inside the container and arrangements between producers and suppliers. While most containers originate in China and Southeast Asia, cargo container measurements take place in ports across the world, because the same gases are encountered in all ports. The idea of the measurement is to screen the toxic containers from the clean containers and to ensure that the...

GASMET FUMIGATION APPLICATION AND DX4040 SPECIFICATION Gasmet DX4040 FTIR (Fourier Transform Infrared) gas analyzer is used for container measurements to measure fumigants and other emitted gases (Figure 2). The battery powered backpack-size analyzer records infrared spectra at 10 scans/s and is capable of sub-ppm detection. The DX4040 requires no span gas calibrations and only a short zero procedure needs to be undertaken before measuring. The analyzer is controlled by a standard laptop computer or a rugged PDA (Personal Digital Assistant) which allows simultaneous analysis of 25 different...

Table 2. Typical gases with measuring ranges for container application. Compound Name Unit Compound Name 11 Foodstuff, 21 Wood and plywood shipping materials, 3) Refrigerant; kitchenware, A/C units, 41 Solvents, plastic goods, 5) Rubber shoes, tires, 61 Inks, printed materials, 71 Medical supplies, 8) Fumigant Copyright Gasmet Technologies Oy 2016 Page 4

MEASUREMENT TECHNIQUE The measurement of air quality inside a container takes some time and the procedure may cause delays, which in turn increases costs. In order to save money and time, the target is therefore to employ an analyzer which measures as many toxic gases as possible, as fast as possible, and still gives reliable results. It is important to minimize “false positives“, since each wrong result causes unnecessary work and creates extra costs. However, experience has shown that “false positives” are considered to be more acceptable than “false negatives” which can result in a...

ADVANTAGES OF FTIR IN FUMIGATION MEASUREMENTS The DX4040 performs simultaneous analysis of up to 50 gases with compensation for cross-interference effects. This is one of the greatest advantages of the Gasmet DX4040 because it significantly reduces the risk of accidents. Moreover, the high amount of gases measured in a short time enables the user to measure many containers per day with a single analyzer, which reduces costs since there is no need to buy several detectors or sensors for different gas compounds. Another major advantage is the minimal amount of calibration and maintenance...