The rates went up fast. But instead of lagging, the Vitalight overtook the Aranet immediately, the number racing up in real time. When the Aranet refreshed, it was catching up to the Vitalight but still behind it. The Vitalight was telling me this was bad now, while I was waiting on the Aranet to give me the reading.
The Vitalight's alarm went off at 800 (beeping twice) as its arrow moved from green to yellow. The Vitalight number raced higher and the Aranet refreshed again -- now closer to the Vitalight. The Vitalight's two-beep alarm went off again as its risk category arrow moved to Orange. I was ready to flee but waited for the Aranet to refresh -- and then it did, at a higher number than the Vitalight, having overtaken it.
Violet reviews the Vitalight and Aranet4 CO2 sensors: