Jonassen K., Pedersen P., Riis A., Sorensen K., 2012, Does the Choice of Olfactometric Laboratory Affect the Efficiency of Odour Abatement Technologies?, Chemical Engineering Transactions, 30, 43-48.
In 2010 during a test of a biological air cleaner 16 samples in triplicates were collected before and after the air cleaner over 8 weeks and analysed within 30 hours at two Danish laboratories and one German laboratory. There was a significant difference between the results from the three laboratories. The mean values of odour concentration from the laboratory with the highest results were up to 27 times higher than those from the laboratory with the lowest results (n = 16). Besides the discrepancy between the results from the laboratories, the odour removal efficiency of the air cleaner varied from 16 % to 80 %, indicating that the result of the test of the air cleaner largely depends on the choice of laboratory. One of the main groups of odorants from pig production is the volatile organic compounds containing sulphur, especially hydrogen sulphide and methanethiol, which are considered to be some of the most important and potent odorants. Hydrogen sulphide was always measured when odour samples were collected. Analytical results from one of the Danish laboratories and the German laboratory obtained in 2011 showed that hydrogen sulphide contributes to odour concentration to a different degree in the two laboratories. Both laboratories comply with CEN EN 13725:2003 (CEN EN 13725, 2003) standard and use the same kind of olfactometer.