Testing Chamber Climate

Many fiber materials are hygroscopic, that Is, they take up humidity from the ambient air. This can change their physical properties (for example, tenacity). The humidity in turn depends on the temperature of the air. Hence, the physical properties of fibers and textiles depend considerably on the testing chamber climate. 

The results of textile tests are thus only comparable if they were determined under the same climate conditions. The expenses to ensure a stable testing climate can be considerable. As a result, depending on the clime, different standard climates were defined (DIN EN ISO 139). Many fiber properties depend more on humidity than temperature hence temperature is variable whereas air humidity is not. 

Standard climate of temperate zones Standard climate of tropical zones  

Standard climate conditions are often abbreviated, for example, 20/65. 

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In figure 7 the ideal mixing model is applied for two different test chambers. Climate chamber A had a volume of 52 m and a loading factor of 1 m /m. Climate chamber B had a volume of only 75ml and a loading factor of 200 m /m. It can be seen that the results obtained are in good agreement. 

Artificial weathering tests in climatic chambers in accordance with the following specifications ... 

Sollinger, S., K. Levsen, and G. Wiinsch, Indoor Pollution by Organic Emissions from Textile Floor Coverings Climate Test Chamber Studies under Static Conditions, Atmos. Environ., 28, 2369-2378 (1994). 

Evaluation of VOC and SVOC emission potential of individual products and materials under indoor-related conditions and over defined timescales requires the use of climate-controlled emission testing systems, so-called emission test chambers and cells, the size of which can vary between a few cm3 and several m3, depending on the application. In Figure 5.1 the dots ( ) represent volumes of test devices reported in the literature. From this size distribution they can be classified as large scale chambers, small scale chambers, micro scale chambers and cells. The selection of the systems, the sampling preparation and the test performance all depend on the task to be performed. According to ISO, chambers and cells are defined as follows ... 

Standardized Emission Testing This is probably the most frequent application of test chambers and cells, because indoor related materials and products need to be evaluated for the release of volatile chemicals in order to ensure a healthy indoor climate. Many procedures have been established for different types of products. A very well-known scheme was developed by the German Committee for Health-related Evaluation of Building Products (AgBB) for the evaluation of building... 

Colombo, A., De Bortoli, M., Knoppel, H., Schauenburg, H. and Vissers, H. (1990) Determination of volatile organic compounds emitted from household products in small test chambers and comparison with headspace analysis, in Walkingshaw, D.S. (ed) Proceedings of the 5th International Conference on Indoor Air and Climate, Toronto, Canada, Vol. 3 (ed. D.S. Walkinshaw), Vol. 3, pp. 599-604. 

Wensing, M., Kummer, T., Riemann, A. and Schwampe, W. (2002a) Emissions from electronic devices examination of computer monitors and laser printers in a 1 m3 emission test chamber. Proceedings of the 9th International Conference on Indoor Air and Climate, Monterey, Vol. 2, pp. 554-9. 

In the future the Swedish formaldehyde rules may include other UF-bonded products as MDF-boards and the requirements also may be formulated as emission rates. On the behalf of the National Board of Physical Planning and Building, the Swedish National Testing Institute has performed a study on the emission from products bonded with formaldehyde based resin. The measurements have been performed in a ventilated test chamber at standardized climate in agreement within the work of the European Organization for Standardization, CEN. 16 West European countries are represented in CEN. 

The GEM method is based upon the assumption that the size and shape of the testing chamber does not influence the emission. During the testing the formaldehyde concentration in the chamber will rise and stabilize at a steady state concentration. At constant climate the steady-state concentration or emission rate from the test object depends on the relation between the loading factor and the air change rate. Good air circulation in the chamber is also essential ( ). 

Formaldehyde emission was measured at 23 C and 50 % RH in a ventilated test chamber of 1.0 m, the testing climate recommended by the Intemational Organization of Standardization (ISO) (. ... 

Piade, J.J., S. D Andres, and E.B. Sanders Sorption of nicotine and ethenylpyridine vapor on different materials in a test chamber 50th Tobacco Chemists Research Conference, Program Booklet and Abstracts, Vol. 50, Paper No. 24, 1996, p. 34 Sorption phenomena of nicotine and ethenylpyridine vapour on different materials in a test chamber in Proc. 7th Intemat. Conf. Indoor Air Quality and Climate Indoor Air 96, 4 (1996) 33-38. Organizing Committee 7th Intemat. Conf. On Indoor Air Quahty and Climate, Tokyo. 

With the use of a quartz filter in front of the PUF22 the possible presence of dust in the test chambers was investigated. 50 m chamber air were sucked through the filter. The filter was weighed before and after under the same climate conditions and no dust was found gravimetrically. Even on a special gold-plated filter (nucleopore) which is normally used for determination of asbestos in air there was no detection of dust particles with an electron microscope. 

Salthammer T. (1996b) VOC emissions from cabinet furnitures. Comparison of concentrations in the test chamber and in the cabinet. In Yoshizawa S., Kimura K., Ikeda K., Tanabe S. and Iwata T. (eds) Proceedings of the 7th International Conference on Indoor Air and Climate, Vol. 3, 567-572, Nagoya. 

Colombo A., De Bortoli M., Knoppel H., Pecchio E. and Vissers H. (1993) Vapour deposition of selected VOCs on indoor surface materials in test chambers. Indoor Air 93 Proceedings of the 6th International Conference on Indoor Air Quality and Climate. 

Bumpers or painted test plates are examples for exposure on test rigs. Test chambers are used to simulate climates in the vehicle interior. Individual components or entire assemblies, e.g., instrument panels are tested in these chambers. Glazing and ventilation (slits or fans) of the test chamber have to be configured so that radiation and temperature conditions in the chamber are comparable to those in the vehicle [208]. 

The field and laboratory emission cell affords a portable, nondestructive method of testing the surfaces of potential VOC sources. In addition to its utility as a climatic chamber, it provides valuable information on source strength, which can be used for source apportionment and to formulate strategies for emission control. Wolkoff et al. [85] used it to identify emission processes in a number of building materials, while Jarnstrom and Saarela [66] recently utilised it to show that the dominant source of 2,2,4-trimethyl-l,3-pentadiol-diisobutyrate in the indoor air of some problem apartments was the floor surface. 

To explain this, it can be argued that a not inconsiderable increase in resistance to mass transfer has been set up in the gas phase, which in fact may vary from situation to situation. Such situations are indeed normal in everyday practice. This explains why in practice, especially at low ventilation rates, much lower concentrations are found, than would follow from measurements done in climate chambers with good circulation. Such intensive circulations remain absolutely necessary if determination of the characteristic particleboard parameters is wanted, independant of the test environment. 

Furnishing. The formaldehyde level in a room at actual conditions depends on several factors, and is not an arithmetical sum of various sources (10), (11). In order to estimate the contribution of formaldehyde emission from single pieces of furniture the test objects have been exposed in area to air volume proportions to which they can be found in a small room or a kitchen. The assumption that the formaldehyde level in the chamber and in the actual room is the same, is based on a theoretical model originally developed for particle boards (4). At constant climate the emission from a test object is determined of the relation between the loading factor and the air change rate. 

The equilibrium concentration and the mass transfer coefficient were then used to calculate the steady state concentration in a system with air exchange with the surroundings, using the model presented above. Tests in a 24 m3 climate chamber, in which temperature, relative humidity and ventilation rate could be varied, were run to check the agreement between the calculated and measured values. 

The finishes in table 2 were not tested in the climate chamber/ because the necessary equipment for the controlled application of them to full-size particleboards was not available. 

Most methods can be modified to suit applications, but for specific applications and to accoimt for long-term efficiency, near faithful conditions may be afforded by humidity chamber techniques, such as soil burial or vermiculite bed. Often a combination of tests is worthwhile in order to reflect performance imder actual climatic and environmental conditions. 

The final engineering tests with the civilian mask offered some interesting problems which had not been encountered before. Prior to this test no item of like materials and like construction had been subjected to such severe environmental conditions at Dugway Proving Ground. The tests consisted of storing the masks for 9 weeks in chambers at —65°F. (arctic), +165°F. (desert), and -fll3°F. and maximum humidity (tropic). In addition, masks were stored for 3 weeks under each of these climatic conditions in succession (cyclic). Upon completion of this surveillance, the masks were compared with controls as to physical condition, gas life, and aerosol penetration. 

The field and laboratory emission cell (FLEC) is a microchamber designed for emission testing of volatile organic compounds (VOCs) from, e.g., building materials. In contrast to traditional climate chambers, in the FLEC and other emission cells the test material becomes part of the cell itself. 

The use of FLEC and traditional climate chambers has been demonstrated for several materials and applications by various investigators. SER from materials tested in the laboratory can be ... 

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