The field olfactory-meter

The Nasal Ranger ® field Olfactory meter is the reference for measuring the intensity of a smell in ambient air. The Nasal Ranger ® is portable device for the detection and measurement of odors, to objectively determine and report D/T dilution threshold .

The field olfactometer factor can be used as evidence or measurement tool 

Quantification of odors in the air may be useful in the following cases :

- Daily control operations (i.e. management performance evaluations), 

- Comparison of processes (i.e. assessment of alternatives), 

- One-off events (defensible i.e., tangible evidence)
- Postings (i.e. insurance and license compliance), 

- Determination of compliance (i.e. renewal), 

- Determination of status (i.e. reference for expansion plan), 

- On treatment of odors (i.e. scientific tests), efficiency measures 

- Modeling verification (i.e. dispersion of odors), 

- Determination of sources of specific odor (ie. complaint), 

- Verification of complaints (i.e. issue notification). 

- As organo-leptic instrument, Nasal Ranger Olfacto-meter field, makes the field reliably by relying on scientifically proven methods.

History

In 1958, the public health service of the United States has supported the development of an instrument and a procedure for field olfactory measurement (measurement of intensity of ambient odors) via the aid project A-58-541, A-59-541, and A-60-541. Thanks to this aid society Barnebey-Cheney has designed a known field olfactory instrument called the  "scentometer".

One Nasal Ranger Olfactory meter creates series of discrete dilutions mixed with filtered pure air (charcoal filtered air). The field olfactory meter sets each discrete level of dilution as "Dilution-to-Threshold," D/T ratio (dilution report / threshold). The "Dilution-to-Threshold" report is a measure of the rate necessary to make the odor present in the air non-detectable.

The field olfactory meter defines the "dilution-to-Threshold" (D/T) (dilution report / threshold) as:


Pure air volume (filtered) 

---------------------------- = D/T 

Odorant / fragrant air volume

Monitoring of odor

The Nasal Ranger field olfactory meter rating system is an effective method for measuring the intensity of odors in terms of "dilution-to – Threshold" D/T ratios (ratio dilution threshold). Factory employees, listeners, and local residents can measure odors with confidence either within the limit of a site or in residential areas.

Below are some examples / protocols for applications :

Measures on site - site operators have the unique ability to measure odors at any time of day. Operators can include comments on coming goods, goods of external process, activities or fugitive odors in the air. On site supervision  with the Nasal Ranger can include regular measurements of pre-determined locations or places of passages, areas of storage, property limits,...

random inspection -random inspection or "Random Monitoring" is a commonly used approach. Random inspection results in a compilation of data that can be correlated with the activities of the sites and other meteorological data. Manager / Buyers are often seduced by this type of effective and relatively low cost procedure / system.

Scheduled monitoring - the scheduled monitoring may occur in the form of a daily walk or inspected several predetermined action points. Nasal Ranger data can be correlated with the number of parameters that influence olfactory episodes, such as weather and activities on the site.


Intensive monitoring - A thorough assessment of the generated impact of smells outside of a site and on site may be required to renew licenses or extend sites. An accumulation of data with the Nasal Ranger ® will help differentiate sources or odors responsible which have an impact outside of the site. Thus may classify all potential sources of smells according to their contribution to the olfactory discomfort. The effectiveness of corrective actions may also be measured by field olfactory meter Nasal Ranger.

Action by networks of volunteers - measurement of odor by local residents with the Nasal Ranger ® can be an interactive community task. The main purpose is to collect information, archive then methodically, they are representative of local residents’ living conditions. Volunteers recruited and trained for measurement of odor with Nasal Ranger ® must also be aware of the documentations about odor definitions. Measurement of odors by volunteers with the Nasal Ranger also helps you understand what smell becomes a nuisance and at what intensity.

Complaints of residents - using emergencies numbers or "Hot line" is a common method used by local communities to overcome the olfactory episodes. A plan of action with dedicated employees, to search for and check the olfactory episodes and the level of the intensities with the Nasal Ranger.

Pen Profiling - the air dispersion models to predict the transport and the dilution of odors by wind. A protocol known as the "pen profiling", allows you to calibrate these models. Multiple users with a Nasal Ranger ® , spaced laterally and in the direction of the wind from the source of odor, measure and save the intensities of odors values "D/T". This enables documenting the cartography of the pen. Thus dispersion models and local topography could thus be checked through Nasal Ranger measures.

Regulations of odor

An field olfactory meter ("scentometer") is referenced in a number of regulations. Terminology "Dilution to Threshold" (D/T) and the method of calculation of D/T are also referenced.

Regulatory criteria often defines conformity as :
"... The ambient air is less than 7 D/T" (7 is a purely arbitrary value reached for this example).

How to formulate is important and may be presented in two ways :
Compliance criterion: "... compliance if... less than D/T 7."
Nuisance criterion: "nuisance if... greater than or equal to D/T 7."

In these two examples, if a controller checks a smell with field olfactory meter note 7 D/T

The smell will be a test of nuisance or 

The ambient air shall be non-compliant

Regulations of odors that use the field olfactory meter, c-a-d Nasal Ranger field olfactory meter, define the number of observations and the intervals of time.

Example :

"... Two observations of ground in an hour done every 15 minutes..."

Or

"... Two observations spaced less than 15 minutes to an hour of time apart..."

Protocols are the guides of the field olfactory meter applications are presented in the form of succinct examples and are not exclusive because often integrated into detailed monitoring of odors programs. Similarly, regulations in terms of compliance and odor criteria are presented only as examples and are derived from actual regulations in terms of odors.