Olfactometric Interlaboratory Comparison Test 2005

The technique of olfactometry is a worldwide acknowledged method to determine the odour parameter of odour concentrations. A decentralized olfactometric interlaboratory test has recently been performed, and thus has become internationally accessible. The concept of dispatching the odorant gases in pressurized gas containers to the participants had been validated in a previous test and confirmed by multiple measurements of the test gas concentration. Following a similar test in 2003, 47laboratories from a total of 15 countries participated in this comprehensive olfactometric interlaboratory test. Apart from the reference substance 1-butanol, the odorants Tetrahydrothiophene (THT) and SFREE™ were used. These two odorants are commonly used in Europe as odorants to natural gas. The test had 2 participation options: The first option gave attention to the verification of thedetermination of the odour concentration of 4 different odours. The second option dealt with thedetermination of the laboratory specific precision and accuracy and its check against the requirements of EN 13725:2003 “Air Quality” — determination of odor concentration by dynamic olfactometry"[1] (subsequently referred to as EN 13725).The test showed that approximately 70% of all participants were able to achieve reasonable resultsin defining the 4 odour concentrations. However, only 2 out of 10 laboratories participating in the second test option were able to achieve the European standard criteria. The concept of a decentralized interlaboratory comparison test proved successful and the large number of participants confirmed the necessity of interlaboratory testing series in olfactometry.