Abstract
In the Netherlands field blanks are mandatory when sampling odour emission. Field blanks are matrices that have negligible or unmeasurable amounts of the substance of interest. They are used to document possible contamination during sampling, transport and storage of samples. Although field blanks are well established in odour emission research, interpreting the results needs further attention. This can be attributed to the fact that published information on the topic is rare if not absent. In the present study, general statistical measures of field blanks used in odour measurement research, are reported. The objective of the study was to provide insight in the distribution of field blank values.
During 2013 and 2014, field blanks were analysed as part of regular investigations into odour emissions. Point sources were most frequently observed (87%), as well as the use of diluting stack samplers (72%). It wasfound that average odour concentration and standard deviation of the dataset were 1.39 and 0.379 log(ouE/m3) respectively, both expressed on a logarithmic scale (base 10). Median values of odour concentration of field blanks taken with stack sampler methods, differed significantly from lung sample methods, being a factor two higher. Since the implementation of stack sampler methods requires moreprocessing aids than the lung method, the chances are that that traces of odour are carried over from one sampling sessions to another. This stresses the need for effective cleaning of sampling equipment between sampling sessions.
