Frequently Asked Questions


What is the Smell Inspector?

The Smell Inspector is a developer’s kit and ready-to-use gadget in one. For anyone working on smart systems – from developers or scientists to tinkerers. It can be trained to detect and distinguish specific smells. This way it can be used by manufacturers who want to control their production environment and the quality of their products, for instance.

How does it work?

Our Smell iX16 detector chip has 16 channels. The Smell Board iX 16×4 currently contains four Smell iX16 chips of different modifications. Thus, the Smell Inspector has an array of 64 gas sensors (channels). Every 1.8 s, we record the change in resistance on each of the 64 channels. Our smell detection is based on pattern recognition. Each scent (as well as each single gas) produces a unique pattern of 64 signals from the 64-channel sensor array. Theoretically, the number of unique patterns, which can be produced with 64 independent sensor channels, is huge. On the other hand, all these patterns, which correspond to different scents, have to be recorded first. We would like to encourage the community to help us with establishing a digital smell database. We will supply our software with a limited initial data collection (the size of this data collection is not defined yet), which will grow with time as more new scents are recorded by our customers and shared with us. On the other hand, every user of Smell Inspector will be able to create his own local smell data collection for his own use.

Which gases and smells can it detect?

Some tested gases and smells: ammonia, nitrogen monoxide, phosphine, carbon dioxide, hydrogen sulfide, ethanol, acetone, isopropanol, toluene, hydrogen peroxide, formaldehyde, 2,6-dimethaxy-phenol, 2-methoxy-4-vinylphenol, guaiacol, some perfumes, chocolate, wine, vodka, coffee, tee, lemon juice, onion, garlic, banana, orange, potato, meat, fish.

How sensitive is the gas detector?

We have benchmarked the sensitivity of our detectors with respect to some standard test gases. So, the limit of detection of our chips is below 80 ppb for NH3, PH3, H2S and NO.

When multiple smells are present how does the device separate them for reporting?

A mixture of smells is also another smell. At best you record the digital pattern for this particular mixture as a new smell in your smell data collection. On the other hand, if all components of the mixture are present in the data collection but not the mixture, our software will try to interpret a new smell as a composition of the known components.

What is the format of the reception data of each smell?

The readout format is ASCII. ASCII is a standard for the representation of characters by electronic devices.

Can the Smell Inspector transmit smells?

No, the Smell Inspector does not transmit smells. But it can be combined with other technologies that could release smells.

Will I be able to replace all these sensors (CO2, CO, NO2, O3, VOC, PM2.5) by your technology?

Yes, this is the idea. The Smell Inspector is both Smell Detector and Multi-Gas Analyzer – as you define it to be! Please be aware that Smell Inspector is designed for qualitative detection and distinguishing of gases and smells and does not provide gas concentrations. For this you will need to perform calibration. Further, the Smell Inspector does not detect particles.

How can the Smell Inspector be handled?

For first steps with the Smell Inspector we provide a handbook and some reference examples for smell detection.

Do you have (peer reviewed) papers published that describe and verify the operating principles of your technology?

Our first research results on gas sensing were published here: L.A. Panes-Ruiz, et al. (2017), “Toward Highly Sensitive and Energy Efficient Ammonia Gas Detection with Modified Single-Walled Carbon Nanotubes at Room Temperature”, ACS Sens. 2018, 3, 79−86, DOI: 10.1021/acssensors.7b00358

What nanomaterials do you use?

We use modified single-walled carbon nanotubes produced by us: “smart nanotubes”.

Is it planned to add this circuit to smartphones?

At the right time, why not?

How do you compare to other gas detecting technologies?

The biggest difference between conventional single gas detection and our gas/smell detection technology is that the latter is based on pattern recognition. A specific digital pattern produced by the sensor array in response to a gas or a smell is compared to the stored patterns. The detectors are based on nanomaterials which make the detectors highly sensitive (see the question on sensitivity). The power consumption at the detector is below 0.001 mW which is several orders of magnitude lower than that of e.g. MOX sensors. Our detectors are less than 1 sq mm in size and the detector chips are very compact and can easily be integrated in various appliances. Moreover, thanks to our production technology the detector chips can be fabricated fully in house for an affordable price.

When will expected delivery be?

We have confirmed with our German production partner Turck duotec that a realistic shipping date will be November 2021.

Will the detectors be (user) replaceable? How expensive will detector replacements be? Or do degraded detectors mean having to buy a new device?

It is a plug-in PCB. So detector chip replacement can be done by yourself. Additional detectors can be ordered as a set and should be very affordable.

How do you train it to detect certain smells? And is it possible to sample a smell and then compare it with new readings?

We use Smell Annotator software to control, annotate and store measurements of the Smell Inspector as well as to recognize annotated smells. Yes, you may sample a smell and extend your digital smell data collection to compare the stored smells with new readings.

Is it necessary to clean the chip after contact with particles or gas molecules?

No, this is not necessary!

Does it have a selfcheck function?

Yes, it does!

Where can I buy the Smell Inspector?

Smell Inspector can already be purchased from our product page. To make a purchase, please go to