This report presents the results of investigations to establish the performance requirements for odor emission measurements for rendering plant process emissions, based on a dilution-to-threshold ratio technique. An in-situ dynamic dilution system, was used as the reference method. In this method the odorous emissions were continuously vented directly from the sample point to an eight-member olfactory panel by means of a dynamic system installed in an on-site mobile odor laboratory. The effects of sampling factors, such as container materials, storage time (aging) of samples, etc., on the validity of odor measurements were evaluated. In addition, the effects of panel selection and training procedures, number of panelists, etc., on the accuracy and reproducibility of odor measurements were determined. Finally, correlations between chemical measurments and dynamic odor unit levels were developed. (Modified author abstract)