How To Detect Stinky Armpits

I would say the easiest, fastest and cheapest way to detect if you have stinky armpits is by lifting up your arm to take a sniff off the armpit in question. Voila, if it stinks you got stinky armpits. But Japanese of course would never sniff armpits in public, so they have a detector for that. With a scale on display from 0 to 10 where 10 is the stinkiest.
From their product page:The process only takes around ten seconds, during which time Tanita’s ES-100 device analyzes for smell-produci