![Sample our Medicine, Dentistry, Nursing & Allied Health journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/5944/TOC-Subject-Sample-2021-Medicine-Dentistry-Nursing-Allied-Health.jpg"})
Abstract
Variations in humidity and temperature cause variations in the intensity of perception of the odours of pure substances. In our research we aimed at effectuating a measure of this phenomenon which could be expressed numerically, and with this in view, we chose the olfactory threshold, i.e. the minimal concentration of the substance under examination capable to originate an olfactory sensation.
We set up an apparatus adjusted to give a wide range of well-defined concentrations of odour substance. It was found that, under equal circumstances, the threshold concentration depends on the temperature and humidity of the inspired air.
In the experiences referred to in this report variations in threshold values have been examined for most common humidity and temperature conditions. A relationship has been determined which allows prevision of threshold values of pure substances in function of temperature. The use of an olfactometer which allows exact concentration of odour substance in the air flux, has made direct and systematic measures of the threshold sensitivity possible. The threshold value has been defined as the minimum quantity of odour substance per unit volume of air inspired (moles per litre) necessary to give the sensation.