Gadget to detect cigarette smoke?

An elderly family member living in an apartment complex is allergic to cigarette smoke. Unfortunately, the guy who rents the apartment below hers smokes inside his apartment, and the smoke gets into her apt through the HVAC system and bothers her.

The property management hasn't been able to stop the guy from smoking because they are required to give notice before inspecting an apartment, and the smoker guy gets rid of the evidence by using air purifiers and smoke-masking sprays before the home inspection.

Is there some gadget that will detect indoor smoking?

Thanks much for any help and suggestions!

The human nose, which is free. Have the manager go inside the family members unit when the smoke is apparent and smell away.

The below gadget might provide proof to the management. Question and answer is from Amazon reviews.

"Question:Will this work for smoke coming from another apartment through the floorboards?
Answer:NicoTests Super-Sensitive Be Sure Nicotine is Out of Your Body, 1.4 ounces, 5 tests per pack

This is the best one. I had smokers below me and as testing at almost the level of a smoker, just a hair below."

Hmm, the Amazon product is a urine test. Wonder if it will help. And smoker guy is sneaky so the property managers' noses don't help my relative, unfortunately. Thanks for the suggestions though, Isamorph.

Sorry, my goof. I should have read more. The one review of the product led me astray.

No worries, Isamorph, no apology needed. You have been so helpful so many times, what's a goof here and there between friends! Incidentally, the battery-alarm app you had suggested (in a different thread) -- I downloaded it after you wrote about it. Thanks for suggesting it - it works very well, no irritating ads, incredibly useful.