INKBIRDPLUS Portable CO2 Detector Mini Indoor CO2 Monitor for Home & Office | NDIR Sensor, Full Color LCD Indicator Light, Alarm, Auto Calibration, Ideal for School, Car, Travel

I am attaching the picture of the Inkbird PTH-10C along with my one year old QingPing AirMonitor Lite. The readings from QingPing AirMonitor Lite are instant and are pretty accurate but I got the wrong readings upon unboxing from inkbird, then I did a 200 sec manual calibration and it started giving correct readings. Max difference between both the instruments is between 25 ~ 30ppm. But the Inkbird (left) needs calibration, and QingPing(right) is much faster in detection and does not need 200sec calibration like Inkbird and it auto calibrates and you wont even in know, its that fast. Inkbird is still very good because of the battery backup, accurate readings post calibration, its not great because its not fast and needs calibration every month. But for the price its a no Brainer. And as per breathefreshair forum review it gives closer readings to aranet.

Not for scientific purposes but works well to give a reasonable data about C02. Good battery life

It's very useful in daily life. Improves the health consciousness.

Fantastic carry anywhere co2 Monitor...really helpful in crowded restaurants and you will soon realise how badly ventilated they are..The other day it shower 2500ppm on a not so crowded restaurant. Also helps on car drives to keep in cabin reading below 1000ppm and can switch outside air circulation when needed. High co2 in car can lead to fatigue on long drives. There are other meters which give additional information like AQI, humditiy and temp but this is pocketable and discreet to be carried anywhere

No reason i can think of to give it any less than 5 stars. This is well designed palm sized co2 sensor. I just received it but I already get a good feeling about its design. The output is sufficiently averaged to avoid measurement spikes if someone takes a couple of breaths close to it. It is easy to calibrate using ambient air so no co2 cylinder needed. Accuracy may not be lab grade but that's not the use case and even the labelling indicates this. I'm adding scans of the operation manual which I missed while shopping, perhaps it will be useful to someone else.

Build quality is good, screen is good and easy. But the only thing that is bad and is also important is the reading time, it is quite slow.

I initially purchased this CO2 meter to monitor CO2 levels in my agriculture room, where higher concentrations of CO2 are quite common. At first, the device worked well—it accurately displayed elevated CO2 readings between 2200–3800 ppm inside the room and normal levels of 400–500 ppm outside. This gave me confidence in its performance and reliability. However, after just 4–5 uses, the device began consistently showing readings in the range of 400-500 ppm, regardless of the location. Whether inside the agriculture room or outside in fresh air, the readings remained almost identical, which is clearly inaccurate given the expected CO2 variation. It seems the sensor has either malfunctioned or lost its calibration too quickly, which is disappointing for a device meant for repeated agricultural use. I would advise potential buyers to consider long-term reliability and calibration support when choosing a CO2 meter for such environments.

had to return as faulty. Replacement working fine. Instructions manual has text size too small to read, had to photograph it and zoom in on computer to read