Overview

An anemometer measures wind speed and direction. It is also a common instrument in weather stations

Scentroid Anemometer

Scentroid offers seamless integration of anemometers with its environmental monitoring devices, enhancing the precision and depth of air quality and odour monitoring. Whether through a weather station attachment for stationary analyzers or the DR2000 anemometer attachment, Scentroid’s devices are designed to incorporate wind data, providing comprehensive insights for environmental analysis.

Anemometer Integration with Scentroid Devices

Stationary Analyzers with Weather Station Attachment

Scentroid’s stationary analyzers, such as the SL50 or the CTair, can be equipped with a weather station attachment with an integrated anemometer. This setup provides real-time wind speed and direction measurements with air quality data, offering a complete picture of environmental conditions.

By capturing critical meteorological data, including wind speed, direction, temperature, and humidity, the weather station attachment enhances the accuracy of air pollution and odour dispersion models. This feature is valuable for industries like sewage treatment plants (STPs), landfills, and industrial facilities where understanding the movement of pollutants or odours is crucial for compliance and environmental safety.

.DR2000 Anemometer Attachment

The DR2000 Drone-based Anemometer attachment allows Scentroid’s mobile air quality monitoring devices, including UAVs (Unmanned Aerial Vehicles), to gather wind data while conducting airborne surveys. This attachment measures wind speed and direction at various altitudes, making it ideal for monitoring hard-to-reach or hazardous areas.

The DR2000 is particularly useful for odour and pollution dispersion modelling, as it provides vertical wind profile data that helps industries assess how pollutants or odours are carried in the atmosphere. This portable, high-precision tool is valuable for monitoring sites like landfills, factories, and power plants, where stationary monitors may be limited in range.

Benefits of Anemometer Integration

Enhanced Data Accuracy: By adding an anemometer to Scentroid’s air quality monitoring devices, users can access real-time wind data that significantly improves the accuracy of odour and pollution dispersion models.

Comprehensive Environmental Monitoring: Combining wind measurements with air quality data allows for a more thorough assessment of environmental conditions, helping industries understand how emissions behave in varying wind conditions.

Regulatory Compliance: With precise wind data, businesses can better meet environmental regulations by improving their emission control strategies and ensuring that pollutant and odour levels remain within acceptable limits.

Versatile Applications: Whether stationary or mobile, Scentroid’s integrated anemometer solutions offer flexibility for various industries, from fixed-site monitoring to drone-based surveys.

The post Anemometer appeared first on Scentroid.

Members are evaluated to determine if they are fit candidates for odour measurement.  Specific criteria must be met, for example, age etc.  In the EN13725 standard, n-butanol is used to determine what a person’s olfactory response may be. 

The post Panel Screening appeared first on Scentroid.

The post Panel Member appeared first on Scentroid.

The inability or decreased ability to perceive an odour as continued exposure to that odour increases over time.  An odour may initially be strongly detectable but may diminish completely in a few minutes. Hydrogen sulphide is an example of a chemical that emits a rotten egg smell, but depending on concentration and exposure time, the rotten egg smell will no longer be perceived even though it is still present.  Olfactory fatigue is not desired during olfactometry analysis or ambient odour monitoring.  In the “EN13725 standard”, are allowed for a series of measurements during olfactometry analysis.

During ambient odour monitoring, it is desired to provide rest periods in a neutral environment compared to the one odour is present if possible.  An example may include a vehicle, which may act as a separate environment to the one ambient odour monitoring is taking place. Perfumeries use coffee bean odour to ‘reset’ the olfactory sense. Also, having neutral odourless air to be smelled for a few minutes may help reset the olfactory sense.

The post Olfactory Fatigue appeared first on Scentroid.

Pertaining to the sense of smell. It is the least understood of the five senses.  No device exists that has the ability to measure odour response as the human nose. The process of olfaction essentially involves a molecule that stimulates nerve cells called olfactory cells where this information is sent to the brain for interpretation.

The post Olfactory appeared first on Scentroid.

The process of analyzing the responses of odour(s) using human subjects (assessors). The responses can be used to determine the odour concentration of odour intensities or the hedonic tone of the odour. Assessors will use a series of devices known as olfactometers.

The post Olfactometry appeared first on Scentroid.

A device that is used to determine odour concentration, odour intensity and hedonic tone. This is achieved by diluting the odour sample with odour-neutral air, which is then presented to a panel. The dilutions may be done by volume or flow-rate and are referred to as a static olfactometer or dynamic olfactometer respectively.

The device may be a mobile unit or permanently in place. It is important to note that the olfactometer should be in an odour free environment so as to not to interfere with measurements. Materials used in an olfactometer must be an odour neutral substance such as stainless steel or PTFE.

Olfactometer Range

According to the EN13725, the range of an olfactometer shall be less than 2⁷ to at least 2¹⁴, with a range of 2¹³.  The presentation of diluted air (neutral gas and odour sample) is to be at least 20l/min.

A full list of Scentroid olfactometers can be found here.

The post Olfactometer appeared first on Scentroid.

American and Australian Odour Unit (OU)

One odour unit is a number where a panel is presented odours in decreasing dilution (increasing concentration) until detection. This is termed the detection threshold (DT) and is 1 Odour Unit.  Above all, if a sample were diluted 500 times, the odour concentration is 500 dilutions / 1 OU of the sample. This would result in 500 OU.  This can be expressed as ‘dilutions to threshold’.  However, the panel can only detect at 1OU (the detection threshold) and not 2OU for example.

European Calculation (OU_E/m³)

One European Odor Unit, [OU_E/m³], is the amount of odourant(s) evaporated into one cubic metre of neutral gas. At standard conditions, it elicits a physiological response from a panel (detection threshold). Above all, This is equivalent to that elicited by one European Reference Odor Mass (EROM), evaporated in 1 m³ of neutral gas. One EROM is equivalent to 123microg n-butanol.  Subjects are standardized to n-butanol which is the reference material.  When odours are detected at the threshold, it is expressed as a multiple of the reference material.

For reference, 1 EROM ≡ 123 µg of n-butanol ≡ 1 OU_E for the mixture of odorants

Should you have any questions, please visit our academy by registering here. Alternatively, you can contact us by clicking here.

The post Odour Unit (OU) (OUE) appeared first on Scentroid.

A location or object that emanates odours. Sources can be divided by point, area, or volume sources that are of either passive, active or fugitive type. For example, a rectangular oil pond would be labelled as a ‘passive area source’ and a biofilter may be labelled as an ‘active area source.’ The term diffuse source is used to describe area or volume sources. Fugitive samples are essentially unintended releases of odour. A summary is shown below:

Point source > Passive or active or fugitive

Diffuse source  > Area source or volume source  > Passive or active or fugitive

The post Odour Source appeared first on Scentroid.

A measure of how strong an odor may be based on an initial perception. Odor intensities and odour concentration have a non-linear relationship. For instance, if two distinct odours are both at a concentration of 3 OU/m3, the resultant intensity measurement may result in one being more offensive than the other.  For example, a low odour concentration of hydrogen sulphide (rotten egg smell) may have a higher odour intensity due to the nature of the smell.

VDI 3882 Qualitative Scale

The German standard Olfactometry Determination of Odour Intensity VDI 3882 Part 1 outlines a qualitative scale to measure odour intensity shown below:

Unlike measurements of odour concentration that take place at the detection threshold (1 OU/m3), odour intensity measurements are taken at and beyond the detection threshold. Note that the odour concentration is known for each odour intensity measurement since the detection threshold is known a prior and can be adjusted by changing the dilution.

Once odour concentration and intensity are determined, they can be expressed as a nonlinear mathematical relationship.  Intensity increases linearly with the logarithm of the odour concentration.  Some formulae include Weber Fechner Law (exponential function) and Stevens Law (power function). 

Webner Fechner Law (Exponential Function)

Webner Fechner Law is shown below:

I = kw log(C/Co) + const

Where:
I: Odour Intensity
kw: Weber-Fechner constant
C: Odour Concentration;
Co: Concentration of odorant at the detection threshold (by definition equals 1OU when using odour units);
const: a constant which relates to the use of mean intensity levels that can be calculated from the line of best fit for each odorant.

An example calculation can be found in the German Standard VDI 3882 for the Webner Fechner Law.

Steven’s Law (Power Function)

Stevens Law is shown below:

I = k(C)ⁿ

Where:
I represents odour intensity
C:  odour concentration
K: constant
N:  exponent

A straight line in logarithmic coordinates appears if function plotted as:

log I = log K + nlog (C)

The post Odor Intensity appeared first on Scentroid.