Snap & Sniff Odor Threshold Test

The Sensonics Snap & Sniff Threshold Test Kit is comprised of 20 sticks. 5 of them contain no odor, whereas the other 15 sticks contain dilutions of phenylethanol (a rose like smell). The Snap & Sniff threshold test can be used to determine the smell threshold using a staircase test procedure.

This test includes an ergonomically-designed carrying case, registration forms and English administration manual.

Threshold smell test

The Snap & Sniff odor threshold test has 20 sticks, 5 of them contain no odor, whereas the other 15 sticks contain half-log dilutions of phenylethanol (a rose like smell) ranging from 10^-2 (strongest) to 10^-9 (weakest) vol/vol concentrations.

Each time 2 sticks are presented to the testperson, one after the oter. The task of the testperson is to report which one (the first or the second stick) seems the strongest.

The presentation of the odor is simple, push the slide mechanism on the stick forward and the odorized tip is exposed. Releasing the slide mechanism retracts the odorized tip back into the stick (wand’s housing). Because the odorant is presented briefly, the odor is retained for much longer periods and can be used for testing many more subjects than devices lacking such sophisticated technology.

The odor threshold test administration will take around 10-15 minutes. The test can be performed as a bilateral evaluation (both nostrils) or as a unilateral evaluation.

Test procedure Snap & Sniff odor threshold test

1. Take one of the rods (sticks) from the box. Present the sticks in the order as indicated on the response form.
2. Hold the tip of the rod under the subject’s nose, close to the nostrils (1-2 cm).
3. Press forward with your thumb on the sliding collar to release the odor and indicate aloud the sequence number of the presented stick; “here’s the first one”.
4. Hold for approx. 3 seconds and instruct the testperson to smell.
5. After presentation, close the odor tip by releasing the sliding collar and place the stick back into the box.
6. Repeat the previous steps with the second stick and indicate; “here’s the second one”.
7. Ask the testperson to provide an answer indicating which of the the 2 sticks is the strongest, the first or the second one.
8. Always start the test with concentration level -6 log.
9. Present the pairs of concentration levels in the order indicated in the sequence column corresponding to the evaluated concentration level. The letter O stands for odor and B for empty (blank). The letter in the sequence column indicates which sticks should be presented first in a pair. Each sequence column has a total of 5 O’s and B’s. Follow the sequence in a column from top to bottom. To ensure the correct order of completion, corss out the letter in the column with a single line after you have presented that sequence pair to the subject.

Recording of responses

• At the bottom of each registration form, there are columns of 5 O’s and B’s. Each O indicates a pair where the odorant is presented first, and then the blank. Each B indicates a pair where the blank is presented first, and then the odorant. These columns are read from top to bottom.
• The initial odorant presentation (O first, then B) is made at the -6.00 log concentration step. On each trial, a correct response is signified by placing a “+”in the box in the row related to the concentration step. An incorrect response is signified by placing a “O” in that same box.
• If a miss occurs on any trial before 5 consecutive pairs are corretly completed at that concentration, the next trial immediately begins at the concentration 0.5 log step lower (one lower box).
• From this point on, present only 1 or 2 attempts by pairs at a particular level of concentration:
  • If the 1st attempt fails, the 2nd attempt is not presented and the next attempt is started in a higher square (0.5 higher concentration level).
  • If both attempts are successful, the next attempt is started in a lower square (at 0.5 lower concentration level).
• The test is completed after a total of 7 staircase reversals are completed. If someone has no sense of smell then the staircase goes to the top and no reversals usually occur.

Refilling the Snap & Sniff tests

Are you using the Snap & Sniff test and do you want to refill them? We can refill the sticks (wands) for you and send them back. This will give you recharged wands so you can continue using the same kit. This is a sustainable way of smell testing and prevents unnecessary waste.

Contact us for more information about refilling the Snap & Sniff tests.