Current technology, odor can be measured in 3 ways. As Alize, we recommend the Olfactometry method. When contacted regarding the subject, we support both odor measurement and odor treatment. There are countless odor sources in nature and in industry, and we approach each odor problem separately and produce solutions for solutions.
1. The Olfactometer Method
Olfactometer: It is named as the device used in the measurement of deodorization.
Determining ranges of known odor concentrations using the human sense of smell.
To detect unknown odor concentrations using the sense of smell as a detector.
It is a measurement method based on interaction. The effect of odor on the sense of smell is measured. It is not possible to measure this effect with physical or chemical sensors.
With this method, 3 parameters can be measured to determine the character of an emission source.
A- Odor concentration
B- Odor intensity (unnoticeable / quite strong-7 levels)
C- Odor quality (pleasant/unpleasant – 9 levels)
The team that will make the measurement consists of 4 panelists and a measurement leader. The measurement leader determines the dilution level of the odorous gas to be given to the panelists. The leader randomly sends diluted gas into the scent mask of each panelist. As soon as the panelists smell the scent, they respond to the leader by pressing a button. The measurement process is carried out by computer control. Odor levels are determined according to the perception levels of the panelists. The results are statistically evaluated by the computer program and the result can be printed on the printer.
Selection of Panelists
Panelists should be familiar with the testing procedure. Panelists should be sensitive to smell. Individuals who can be considered as “normal” to smell can be panelists. The olfactory sensitivity of the panelists is determined by the results of a series of tests with N-Butanol. As the number of panelists increases, the accuracy of the measurement increases. Normally, 4 panelists are sufficient.
- Full calibration is possible.
- The result obtained does not depend on chemical components.
- It is a reliable determinant.
- It is not a permanent method.
- Many employees are needed.
- It is a subjective method (Personal)
2. Electronic Sensors
In different research and development centers of the world, copies of the wonderful olfactory system in humans are tried to be produced. These models, developed by taking the nose as an example, are called “electronic nose”. In place of the receptors made up of proteins in the human nose, a number of chemical receptors are used in their electronic counterparts. Each of these receptors is designed to detect different odors; As their selectivity capacity increases, their production becomes more difficult and their prices increase.
It is quite difficult to determine the correct odor intensity with electronic sensors:
A- Variety of odor sources
B- Effective environmental factors
C- Environmental factors are effective
D- The measured odor intensity depends on the chemical level in the odor.
The signals collected by the sensors from the environment are converted into binary codes via electronic systems and sent to a computer. Electronic systems can be thought of as an imitation of the nerve cells responsible for the sense of smell, and the computer as an imitation of the human brain. The computer is programmed to evaluate the information it receives, and thus interprets the binary coding signals it receives.
- Can make repeatable measurement
- Sensitivity is high for certain scents
- Continuous measurement can be made.
- Over time the sensors can become dirty.
- It is sensitive to moisture.
- Calibration accuracy decreases over time.
3. Gas Chromatography / Mass Spectrometry
Gas chromatography is a method used to separate very similar mixtures. The composition of the gas mixture can be found by this method. Where very precise qualitative and quantitative analyzes are desired, a mass spectrometer (GC+MS) is added after gas chromatography.
- Even very similar mixtures can be distinguished.
- Precise qualitative and quantitative analysis is possible.
- It is costly.
- It is not practical.
- It takes a long time.
- The use of GC/MS + Odor Mask is both difficult and impractical. The use of electronic sensors is not always appropriate for characterizing the odor as pleasant/unpleasant. The human nose is the most effective sensor that can be used for odor measurement.