Continuing the discussion from Indoor/outdoor air quality monitor: Ecowitt WH0290:
The indoor/outdoor air quality monitor just arrived!
The sensor unit has a black base that comes off to reveal space for two AA batteries and a micro-usb hole. This unit came with two rechargeable AA batteries, and you are meant to recharge these batteries by plugging the whole unit into a wall plug via the micro usb port. It also has a solar panel to recharge its own batteries if it is mounted outside. It is supposed to be rainproof.
The display unit requires its own AA battery that you have to supply, yourself. I put in one of my Anker rechargeables.
(I was initially confused and had put one of the two AA batteries it came with into the display unit before figuring out that it was intentional of them to only give two AA batteries and they were specifically for the sensor unit only.)
The sensor transmits data every ten seconds maybe? Or every sixty seconds?
The display unit shows current pm2.5 and current AQI, as transmitted from the sensor unit.
The display also shows the temperature and humidity, but from the display unit’s own sensors, NOT the air quality sensor.
The display unit must have some onboard memory, because it can also display the max pm2.5 and max aqi detected in last hour, in the last 24 hrs, or the max detected since the last time you reset its memory (by holding down one of the buttons for two seconds). I currently have it showing the mac detected in the last hour.
I have not tried it outside yet. I’m going to let the batteries charge now and leave the unit plugged in until the blue light turns off.