There are a bunch of different sensors out there, based on price and sensitivity I have chosen to buy two different sensors the TGS822 from Figaro sensors and the MQ-3 from HANWEI ELETRONICS. If i wasn’t on a budget I would also have ordered a WSP2110 –  air polution detection since I believe that a combination with on of the TGS882 or MQ-3 with the WSP2110 could be a good match where the WSP2110 is has a sensitivity range between 1-50 ppm and the other two has a range between 10-1000 ppm. So the combined result of both could give us a more granular scale at lower concentration levels.

Figaro Sensors

TGS822 – Alcohol (ethanol) gas sensor, gas sensors is a tin dioxide (SnO2) semiconductor.

HANWEI ELECTRONICS CO.,LTD

MQ-3 – Alcohol Gas Sensor, is also a SnO2 sensor so it should have similar detection abilities as the TGS822 but acetone is not mentioned in the data sheet. According to one manufacturer this sensor has a detection range between 10-1000 ppm for alcohol and then about the same apply for acetone.

MQ303A – Alcohol Gas Sensor, is essentially the same sensor as the MQ-3 however it works on a lower voltage. One serious disadvantage with this one is that a manufacturer states that the sensitivity of this sensor is 20-1000 ppm.

When you compare the MQ303A with the MQ-3 sensor’s range of 10-1000 ppm I think I will go with the MQ-3 sensor instead of the MQ303A since the concentrations we want to measure is between 0-200 ppm.

WSP2110 –  air polution detection, this sensor has a different ceramic substrate of subminiature Al₂O instead of th SnO2 used in the other sensors and is more sensitive but also has a smaller detection range then the others, 1-50 ppm. it is also a lot more expensive as the other sensors.

ME3A – C2H5OH – This sensor works with a completely different type of chemical process.

”Detects gas concentration by measuring current based on the electrochemical principle, which utilizes the electrochemical oxidation process of target gas on the working electrode inside the electrolytic cell, the current produced in electrochemical reaction of the target gas are in direct proportion with its concentration while following Faraday law”

It seems to be very sensitive and detects between 0-1.000mg/L alcohol per liter, however it also have a price of /piece. Since this sensor works with a completely different technique I am not even sure if it detects acetone as well as ethanol and it is also way to expensive so just forget about this one.