Waking up your Flow Follow
When you first connect to the device, you’ll see scrolling yellow lights on the front of your Flow to let you know that it's in the process of waking up. The gas sensors inside Flow take a little while (about 15 minutes) to get themselves ready to start sensing accurately. This is called Flow's warm-up period.
Please note, every time your Flow runs out of battery, as well as when you update your device, your Flow will need time to wake up.