Emission test chambers

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 ... 

Emission test chamber Enclosure with controlled operational parameters for the determination of volatile organic compounds emitted from building products (ISO, 2006a). 

A so-called Micro Chamber (g-CTE) (see Figure 5.2) with an interior volume of approximately 45 ml has been designed by Markes Int. (Schripp et al., 2007). The X-CTE comprises six individual stainless steel cylindrical chambers (d = 4.5 cm), located in one unit. All six chambers are supplied simultaneously with the same, controlled flow of synthetic air. By reducing the chamber volume, it was intended to reduce typical emission test times but still generate meaningful emission data-i.e. results that correlate with data from conventional emissions test chambers. The g-CTE was not intended to replace standard emission test facilities. In fact it is a complementary tool intended to produce fast information about the composition and level of VOC emissions for development of new, low-emission products/materials. Micro chamber measurements have already been shown to... 

Emission test chambers, cells and analytical procedures are now standardized by ISO, ASTM and other authorities (see Table 5.1). However, it is interesting to note that only the ASTM standards take sink effects (see Section 5.3) into account Different types of testing facilities have different properties regarding amount of test specimen, dynamics, time, result and cost. In a small device the test is generally time efficient, but on the other hand sample inhomogeneities will significantly influence the results. In Figure 5.3 some trends are shown in dependency of the chamber/cell size. 

Dunn, ).E. and Tichenor, B.A. (1988) Compensating for sink effects in emission test chambers by mathematical modeling. Atmospheric Environment, 22, 885-94. 

ISO (2006a) 16000-9. Indoor Air-Determination of the Emission of Volatile Organic Compounds from Building Products and Furnishing-Emission Test Chamber Method, International Organization for Standardization, Geneva, Switzerland. 

Schripp, T., Wensing, M., Uhde, E., Salthammer, T., He, C. and Morawska, L. (2008) Evaluation of ultrafine particle emissions from laser printers using emission test chambers. Environmental Science and Technology, 42, 4338-43. 

CEN/ISO EN/ISO 16000-9 Indoor Air-Part 9 Emission test chamber method Will supercede 13419-1... 

Preparation of test specimens from solid samples invariably requires a portion of the sample to be cut out, for example, from the middle of the original roll or sheet of material. Freshly cut edges are notoriously high emissions sources and failure to adequately seal these and exclude them from the test is a major potential source of error. (Another advantage of emission test cells versus conventional chambers is that they automatically exclude any potential edge effects in most cases.) Similarly, surface emissions testing requires the rear surface of the material (the surface that will not be exposed once the product is installed in a building) to be sealed and excluded from the test. This is always a consideration for emission test chambers but can be an issue for both cells and chambers in the case of porous or permeable materials. 

Figure 8.2 Experimental set-up for material odor evaluation using an emission test chamber.

DIN EN ISO (2008) 16000-9. Indoor Air-Part 9 Determination of the emission of volatile organic compounds from building products and furnishing- Emission test chamber method, Beuth Verlag, Berlin, Germany. 

Wensing, M. (2004) Measurement of VOC and SVOC emissions from computer monitors with aim3 emission test chamber. Electronic Goes Green Conference, September 6-8, Berlin, Germany. 

With the aid of emission test chamber measurements (see Chapter 5) emissions from electronic devices can be determined without any environmental influences affecting results. Such investigations aim at determining device-specific emission rates under standardized environmental conditions. Using these emission rates it is possible to make comparisons between the emission characteristics of different devices not only qualitatively (the composition of the emissions) but also quanti-... 

After switching on (pre-operating phase), the emissions of the device increase and under the boundary conditions of the test (air exchange rate) an equilibrium concentration Cpre establishes on top of the background concentration Cbg of the emission test chamber. During the operating phase there occur the emissions from consumables and heated electronic components. Once the operation has... 

Figure 17.3 Concentration curve for a printing test in an emission test chamber. Emissions without printing are shown in dark gray, printing emissions in light gray (diagram taken from ECMA, 2007).

Table 17.5 Emission test chamber measurements of monitors (initial start-up) with sampling after 6 h of operation SER (pg unir tr ) and model room concentrations (pgm-3) (Wensing et al., 2002a).

Rockstroh, J., Jann, O., Wilke, O. and Horn, W. (2005) Development of a reliable test method for laser printers, copiers and multifunctional devices in emission test chambers. Gefahrstoffe-Reinhaltung der Lufi, 65, 71-80. 

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. 

Kemmlein, S., Bergman, M., Jann, O. (2006) Emission test chamber study specific emission rates of PBDE from selected materials under various conditions. Organohalogen Cpds., 68 488-491. 

Fig. 2 View of a 1-m emission test chamber used in WKI (Photo T. Salthammer)...

Investigation of building products using emission test chambers. 

Table 3 Quality requirements for emission test chamber and emission cell according to EN 13419-1 [12] and EN 13419-2 [33]. TVOC represents total volatile organic compound ...

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