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Sensory Test

The sensory test is conducted in a location where the panel can be relaxed and concentrate on sniffing odors, in where there is no other odors that may effect the test

The Conditions for The Sensory Testing Room

The conditions for the sensory testing room are as follows.
・A room where no odor is detected.  
・A quiet room.
・A place where the sample source cannot be seen.
・A place where the sample preparation is not seen.
・A place where the panel can be fully relaxed.
These conditions for the test room are common to the panel screening test, environmental sample measurement, and exhaust port sample measurement.

3-Folds Series Descending Method

Because the odor of exhaust port sample is generally stronger than those of environmental samples, the dilution ratio is pursued by employing a 3-fold series descending method until the odor cannot be distinguished.
In this method, the initial dilution ratio is determined first, and the panel sniff the odor.
If the panel give answers, the panel sniff a solution that has been diluted 3-fold.
If the panel correct answers again, the solution is diluted further 3-fold, and this procedure is repeated until the panel answers incorrectly.

The operation procedures are similar to those for the environmental sample.

Preparation of Odor Bags without Odor

The preparation procedure for odor bags without odor and odor bags with odor are the same with those for environmental samples and exhaust port samples.The odor bag, which is the most important object in the Triangular Odor Bag Method, should be made of highly odor-free polyester with the capacity of 3 liters when it is completely expanded.

The measurement is carried out in the following procedure. First, an odor bag without odor is prepared using this kind of equipment. Create odor free air through activated carbon.

Before using the activated carbon, confirm it is odor-free. After using it for a certain period of time, or if you feel that activated carbon has become odorous, desorb the odor substances by heating.

Set the odor bag on the distributor. After the odor bag is filled up with odor-free air, confirm that it is odorless, and remove the bag from the distributor. Now, close the odor bag using a silicon stopper. An odor bag without odor is prepared in this way.Prepare 3 odor bags without odor for each panel member. Prepare as many bags as needed.

Preparation of Odor Bag

In determining the initial dilution ratio, the operator must carefully examine the degree of the odor and make the concentration at an appropriate rate, otherwise, strong odor may cause olfactory fatigue on the panel.Select the size of syringe according to the amount of sample to be extracted. Insert the needle into the sampling bag, and extract the necessary amount.
Inject the collected sample into the odor bag. Make a hole with the same syringe needle in the remaining 2 odor bags without odor. 3 odor bags make one set. Prepare one set per panel member.

Preparation of Odor Bags with Odor

Inject the extracted sample into the selected odor bag, to prepare a sample that is diluted tenfold.When injecting the sample, inject it through the hole on the label.

Preparation of Odor Bag

In the remaining two odor bags with the sample not injected, make a hole using a syringe needle that is about the same size as the syringe needle used for injecting the sample, so that the panel does not make judgment on the basis of the presence of a hole. In addition, the odor bags without odor used here can be used again afterwards.Prepare one set per panel member.

Procedure of Judgment

Give the 3 prepared odor bags to the panel member. The panel member sniffs the odor of the given bags using nose cones, and determines which bag has odor. When sniffing, the nose cone should be pressed against the face firmly. The odor should be sniffed while inhaling slowly, in tune with your own breathing.

Answers are always written down on the answer sheet, and never given verbally. Instruct the panel to write down the number clearly, and to not give any unclear answers.Following the same procedure, the samples of 10-fold dilutions are judged two more times.


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