Prof. Sam LawlerUpdate on this: I still have to make a fastener, but I made a very simple little crocheted bag for my #aranet4 yesterday. I may or may not have time to add a button and elastic later today (hopefully?) Thanks for the idea and for confirming a knitted bag doesn't mess with the readings, @JosetAEtzel!
CoolBlenderKitten
aalborg@sundogplanets @JosetAEtzel interesting device. This #Aranet4 is an indoor CO2 meter. Cost is 160 to 200 euro. https://aranet.com/products/aranet4/
Sak@sundogplanets That's adorable! Thanks for remind me I need to find a way to use the wall-mount hole to attach mine to the strap of my bag.
pammack@sundogplanets I bought a number of mesh pouches, and the smallest one in this set is the best fit: https://www.amazon.com/dp/B0C32NHJBS
Jo Etzel@sundogplanets Yes! I #knit this from scrap wool yarn, then felted it in the washer and sewed the sides. The elastic and button closure allows surprisingly good air flow; I usually put the #aranet4 in so that the vents are towards the top.
@JosetAEtzel Oh THANK YOU for sharing this! I"m going to start one one right now!
Idealistic Pragmatist 
@sundogplanets @seawall nothing handmade, but I bought this simple little case for mine! https://shop.evidencebased.ca/products/aranet4-case
Ben Keith@sundogplanets
Not crochet, but there's a number of #aranet4 cases out there:
Here's the semiofficial case: https://aranet.com/print-out-your-own-aranet4-3d-cover-case/
And a couple of smaller cases: https://www.thingiverse.com/search?q=aranet&type=things&sort=popular&page=1