Review on 🏭 Optimize-It: Enhance Your Greenhouse Efficiency with the Day Night Monitor Controller by Chad Carter

I paid for a new device but received a used or returned device. It also doesn't work properly. There is a sticker that says "Remove protective film before use"; There is no protective film on it and there are scratches on the face. No big deal I thought. I calibrated it externally (to 410ppm) as suggested in the instructions and because it was reading 500s. The calibration passes, but after a few minutes it rises to 530ppm. Armageddon isn't waiting for us, so that's clearly wrong. After 30 minutes it shows low 420s. I'm writing this review and I look, it says 523. After a few minutes 410, after a minute 421. I calibrated it, same problem.