The introduction of an international standard on odour measurement presents a new challenge for olfactometry laboratories to meet tough new instrumental performance and panelist performance criteria. The paper reviews a number of olfactometers used in the last ten years both in Australia and overseas. It has found that the back pressure could contribute a significant error in the delivery of the required dilution ratio and the contamination of the olfactometer was the source of large variation in olfactometry results. The paper discusses the instrumental performance of the newly developed olfactometer. DynaScent is a fourth generation olfactometer which uses no flow measurement device (flowmeter or mass flow controller). The dilution ratios of the DynaScent were calibrated using CO gas and auto calibration feature. The effects of the CO sampling point locations (within the system and above the sniffing cup) could have significant impacts on the dilution ratio. Practically, the manual calibration is both time consuming and labour intensive. Furthermore, it was found that the accuracy and instability results were sensitive to the selection of the CO gas range. It is concluded that the calibration of a dynamic olfactometer should be carried out more frequently than once a year. The DynaScent olfactometer was able to achieve averaged instability of 1.7% and accuracy of 9% over the dilution range of 2 – 65000.
Development of the Next Generation Dynamic Olfactometer – Dynascent
Scentroid Odour Regulation