Environmental test chamber control method

The environmental test chamber method is a powerful tool for the comparative characterization of various products and materials under test conditions with regard to their emissions. When choosing the test parameters and when interpreting the results it has to be taken into account that it is a question of a conventional procedure, and that it is impossible to simulate all real conditions indoors. In the future, it will be possible to make frequent use of the results to develop low-emitting products. By selecting such products with the aid of a source control, the environmental test chamber can make an essential contribution to an improved lAQ. 

Load Frame, Force and Strain Measurement, Data Acquisition The test method uses a standard load frame with a hydraulic or screw drive loading mechanism and standard force transducers. Force is applied transversely to produce a bending moment. Extension is measured by deflectometers in the gage section and strain is measured using bonded resistance strain gage rosettes to determine both longitudinal and transverse strains. If required, an environmental test chamber may be used to control humidity and ambient temperature. Data collection should be done with a minimum of 50-Hz response and an accuracy of 0.1 % for all data. 

Thome FA, Heavner DL, Ingebrethsen BJ, Eudy LW, Green CR (1986) Environmental tobacco smoke monitoring with an atmospheric pressure chemical ionization mass spectrometer/mass spectrometer coupled to a test chamber. Proc 79th Annual Meet Air Pollution Control Assoc. Air Pollution Control Assoc, Pittsburgh, paper 86-37.6 Thompson CV, Jenkins RA, Higgins CE (1989) A thermal desorption method for the determination of nicotine in indoor environments. Environ Sci Technol 23 429-435 Thomson BA, Davidson WR, Lovett AM (1980) Applications of a versatile technique for trace analysis atmospheric pressure negative chemical ionization. Environ Health Perspect 36 77-84... 

All quality control tests and specimen conditioning are conducted under carefully controlled environmental conditions, i.e. temperature = 24 H3.5 C, 50h 5% relative humidity and a background formaldehyde level of less than 0.1 ppm. Ourselves as well as others have found that temperature effects on the quality control test values follow the same pattern observed in the large scale chamber (30). In short, the Berge temperature correction can be applied to the quality control test methods. 

To be fully utilized, this chamber should also serve as a resource for collaborative studies where environmental chamber measurements imder highly controlled conditions would be useful. We encourage collaboration with other researchers who have instrumentation that we lack that would be useful for various studies, such as our collaboration with William Brune of Penn State University, whose HO and HO2 radical measurement instrumentation was used with the surrogate - NOx experiments carried out for the observational based methods study. This facility would also be useful as a test bed for evaluating analytical instrumentation for use in ambient monitoring, since it can produce realistic but highly characterized simulated pollution conditions for instrument evaluation and inter-comparisons. 

To demonstrate the reliability of the testing system and the reproducibility of the data, stress-strain curves were measured in five series of tests with batch, loading method, environment, strain rate and adhesive type as variables. All tests were performed in environmental chambers in which RH and temperature were carefully controlled. Loading and data acquisition were computer controlled unless noted otherwise. In the following, the authors use the term initial strain rate as defined in the ASTM Test Method D 882. 

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