The second meeting of the Working Group (WG) 41 that is dealing with the first European Norm that will regulate the so-called “e-noses” took place in Nimes, France, the 11th of February 2016. In this meeting the title of the norm was further discussed. The question raised was: sensors for monitoring odorants or odours?

    Odorant? why not odour monitoring? A clear terminological distinction should be made between odorants (stimulus) and odour (sensation). In the same way that the olfactory system transduces chemical signals into perception (odours), the sensors "transduce" odorant signals into electric signals.

   These electric signals can be compared afterwards with an odour concentration determined by dynamic olfactometry, and yes, you might correlate afterwards, though sometimes it is a hard task. However, at the end of the day, once your sensor is set in a plant, it will not "smell" odours, it will just detect odorants.

   That is why most of the members are not comfortable with the term "e-nose". It might be electronic, but there is no "nose" here.

   However, the term "e-nose", though incorrect, is very handy as it expresses in a short word the aim of the device. Also it is a fantastic marketing name, I think that "sensors for odorant monitoring" does not sound very marketable, does it?

   The committee discussed some other names and somebody mentioned the term "o-sensor" as opposed to "e-nose" but no decision was really made on this matter.

   However, as I am the one writing this article, I like the term plus it is a bit tiring writing all the time "sensors for odorant monitoring" I will be using the term "o-sensor" from now on, until a definite agreement is reached. I hope my colleagues will ever forgive me.

   Besides, a list of definitions from three different norms was selected by consensus. The three norms were the European Norm EN 13725, the Dutch norm NTA 9055 and the German norm VDI/VDE 3518.

   Some examples of systems used as sensors for odorous gas monitoring were discussed and a first list of o-sensors was included in the text. However, is a list of type of sensors really necessary? Will this list outdate the norm if other types of o-sensors are discovered over the process of discussion of the norm? These questions were also discussed.

   An important part of the meeting was the discussion of the division of the work into Task Groups (TG). The TGs proposed in this CEN committee will address the following topics:

• Task Group 1: Minimum requirements for instrumental odour monitoring systems.
• Task Group 2: Establishing and validating the relationship between odour metric and odour.
• Task Group 3: Terms and definitions.
• Task Group 4: Descriptions and review of scope relevant technologies.

   If you find this article interesting, you might also be interested in these articles:

• First Meeting of the CEN group dealing with gas sensors and pattern recognition.
• A new European Norm for e-noses?
• Considerations on Sampling and Measurement of Odours (VDI 3880 & VDI 3885/1) and eNoses