A New Appraoch to Odour Monitoring

Several years ago, Chromatotec developed a new solution to measure levels of the intensity of odour variation called the vigi e-nose. The name of this product was used to compete with other electronic noses (e-noses). E-noses offer a good alternative to dynamic olfactometry measurement to check odour intensity variation. Most of the existing e-noses in the market deploy detection sensors known as Metal Oxide Sensors (MOS).

These technologies provide a global fingerprint using two main principles of detection: non selectivity and cross-interference with humid sensitivity. Some providers try to integrate ‘specific sensors’ such as NH3 or H2S but these sensors are sensitive at ppm levels and cannot reach human nose sensitivity. However, these solutions allow tracking gas variations with additive information in spite of the fact that sensors used are crossed-selective (for example, a non-selective H2S specific sensor is prone to interferences with Mercaptans and ammonia)

Raw data coming from the analysers is calculated and collated by mathematical models using artificial networks or multivariate statistics. This provides results correlated with a reference odour sensory method (as dynamic olfactometry if used according to European standard EN 13725 or ASTM 679 E-4 if US standard is required).

Due to customer non satisfaction with their existing solutions, Chromatotec has developed and deployed their solution initially in municipal Waste Water Treatment Plants in France, UAE and Poland and more recently in sites equipped previously by competitors’ e-noses. Tests were carried out comparing the vigi e-nose favourably with the exisiting e-noses. The revolutionary approach is based on the separation of 14 sulphur compounds, such as H2S, Mercaptans, and Sulphides also including VOC concentration with an all-in-one solution. This turn-key solution offers the capability to reach concentration levels lower than the human nose can detect.

When odour impact measurement is needed, theChromatotec’s latest development of dispersion software development (vigi Odor) allows operators to integrate with standard atmospheric systems such as AERMOD, which is recognised by the USEPA.