1200 mAh rechargeable, Type-C charging, usable while charging
Display
Full colour screen with backlight
Weight
108 g (0.24 lb)
Mounting
Desk standing, or hung by the slots on the back
Weight
108 g (0.24 lb)
Shipping & returns
Tracked delivery anywhere in the United Kingdom. Free on orders of £50 or more; below that the only method offered is Express Delivery at £22, which is also available above the threshold as a paid delivery option. Allow 5 to 7 days, after a 24 to 48 hour handling time. The price shown is the price charged, and no sales tax is added at the checkout.
For most goods bought online, a UK consumer may cancel within 14 days after receiving the goods and then return them within a further 14 days, subject to the statutory exceptions. Contact us before returning anything so we can provide the correct instructions. Refunds are processed within the period required by law.
If it arrives faulty, damaged or not as described, we provide the remedy required by UK consumer law and cover reasonable return costs where the goods are faulty or incorrectly supplied.
Wipe the case with a dry cloth. Do not run it under water. Charge it over the Type-C socket; it keeps reading while it charges.
Reads 400 to 5000 ppmCovers fresh outdoor air at the low end and a badly stuffy room at the high end
Updates Every SecondYou can watch the number move as a window opens
Three Readings, One ScreenCarbon dioxide, temperature and humidity together, no switching modes
Alarm When CO2 ClimbsIt sounds when the reading passes the threshold, so it works unattended
About this product
You cannot see how stale a room has got. This tells you.
A palm sized monitor that reads carbon dioxide, temperature and humidity on one screen, and sounds an alarm when CO2 climbs.
Carbon dioxide is the easiest way to tell whether a room is being ventilated, and the one thing you cannot judge by standing in it.
This monitor shows CO2 in parts per million alongside temperature and humidity, refreshes every second, and sounds an alarm when the level climbs.
It is palm sized at 108 g, runs off a rechargeable battery, and hangs on a wall bracket or sits on a desk.
Carbon dioxide is a proxy for ventilation. People breathe it out constantly, so in a room with too little fresh air coming in the level climbs steadily through the day. Outdoor air sits around 400 to 420 ppm. A room with air moving through it usually stays under 800. Once a reading sits above about 1000 to 1500 ppm, the room is recycling the air already in it. None of that is visible or reliably obvious from inside the room, which is the whole reason a number helps.
This is the compact end of the range. It reads carbon dioxide from 400 to 5000 ppm and shows temperature and humidity on the same screen, so you get the three numbers that describe a room's air without changing modes. The reading refreshes every second, which matters more than it sounds: you can open a window and watch the number fall, which tells you how quickly that particular room actually clears.
The alarm is what makes it useful when nobody is watching. Set it somewhere it can be heard, and it will tell you when a room has drifted rather than waiting for you to check. That suits a classroom, a meeting room, a workshop or a bedroom, where the level climbs slowly and nobody notices.
It runs on a 1200 mAh rechargeable battery and charges over Type-C. It keeps working while plugged in, so it can sit in one place as a permanent monitor, or come off the charger and go in a bag. At 108 g it is genuinely pocketable, and there are slots moulded into the back if you would rather hang it.
If you want a screen readable from across a room rather than from arm's length, the jumbo wall mounted monitor covers the same measurements on a much larger display.
Still deciding?
Not sure yet? That is fine.
For most goods bought online, a UK consumer may cancel within 14 days after receiving the goods and then return them within a further 14 days, subject to the statutory exceptions. Contact us before returning anything so we can provide the correct instructions.
If it turns up faulty, damaged or not as described, we provide the remedy required by UK consumer law and cover reasonable return costs where appropriate. Read the detail on our refunds and returns page, or ask us anything before you order.
Three things on one screen: carbon dioxide in parts per million, temperature, and relative humidity.
What CO2 range does it cover?
400 to 5000 ppm. The bottom of that range is roughly what outdoor air reads, so the scale starts where fresh air sits.
What is a good CO2 reading indoors?
Outdoor air is around 400 to 420 ppm. A room with fresh air moving through it usually stays under 800 ppm. Above roughly 1000 to 1500 ppm the room is largely recycling the air already in it and could do with a window or better airflow.
Why measure CO2 rather than something else?
Because people are the source. You breathe carbon dioxide out all day, so in an under ventilated room the level climbs in a way that tracks how much fresh air is getting in. It is the simplest single indicator of ventilation.
Does it tell me if my air is dangerous?
No. It reports carbon dioxide, temperature and humidity. Treat it as a ventilation gauge rather than a safety or health device, and do not rely on it to detect any other gas.
Will it detect carbon monoxide?
No. Carbon monoxide is a different gas and needs a dedicated CO alarm. This measures carbon dioxide. If you need a carbon monoxide alarm, fit one as well.
Does it detect smoke, dust or particulates?
No. It covers carbon dioxide, temperature and humidity only.
How often does the reading update?
Every second, so you see changes as they happen rather than on a delay.
Is there an alarm?
Yes. It sounds when the CO2 reading passes the threshold, which is what makes it useful in a room nobody is actively watching.
How much does it weigh?
108 g, or 0.24 lb, so lighter than most phones.
How big is it?
Palm sized. It sits comfortably on a desk or shelf and fits in a bag or a large pocket.
Can I hang it on a wall?
Yes, there are slots moulded into the back for that. If you want something readable from across a room, look at the jumbo wall mounted monitor instead.
How is it powered?
A built in 1200 mAh rechargeable battery, charged over a Type-C socket.
Can I use it while it charges?
Yes. You can leave it plugged in permanently and treat it as a fixed monitor.
Does it need batteries I have to replace?
No. The battery is built in and rechargeable, and it charges with an ordinary Type-C cable.
Is the screen readable in a dark room?
Yes, it is a full colour display with a backlight.
Can I see all three readings at once?
Yes. Carbon dioxide, temperature and humidity are shown together, so you do not cycle through modes.
What temperature range does it cover?
33 to 150°F, as the listing states it.
What humidity range does it cover?
0 to 99% relative humidity.
Where do people use these?
Classrooms, offices and meeting rooms, workshops and warehouses, bedrooms, and growing spaces like greenhouses. Anywhere the air gets stale slowly and nobody notices.
Is it useful in a bedroom?
It is one of the more revealing places to put one. A closed bedroom with two people in it climbs overnight, and the reading in the morning is usually a surprise.
Would this help with a greenhouse or growing space?
It reads the same three values, which are the ones growers usually watch. It is a monitor though, not a controller, so it will not regulate anything for you.
Can I use it outdoors?
It is designed for indoor use. Keep it out of rain and direct weather.
How accurate is it?
The listing gives measuring ranges but no accuracy tolerance or calibration figure, so we do not quote one. If you need documented accuracy for compliance or reporting, ask us before you order and we will tell you what we can confirm.
Does it need calibrating?
No calibration procedure is published for this model. If that matters for your use, contact us first.
Can I log or export the readings?
No. It is a live display with an alarm. There is no data logging or export.
Does it connect to an app or wifi?
No. It reads on the device itself with no app or network connection.
How long does delivery take?
Delivery across the United Kingdom takes 5 to 7 days after a 24 to 48 hour handling time. It is free on orders of £50 or more; below that the only option is Express Delivery at £22, which you can also choose on any order as a paid delivery option. No faster transit time is promised for Express Delivery.
What is the difference between this and the jumbo monitor?
The measurements are the same. The jumbo is a large wall mounted display built to be read from across a room, and this one is a portable palm sized unit.
Can I return it if I change my mind?
For most goods bought online, a UK consumer may cancel within 14 days after receiving the goods and then return them within a further 14 days, subject to the statutory exceptions. Faulty, damaged, wrongly supplied or misdescribed goods are handled under UK consumer law. Contact the team before returning anything.
The complete guide
Reading a CO2 number and knowing what to do about it
4 min readCO2 Company UK
What the number means
Carbon dioxide indoors is mostly a headcount problem. People breathe it out, and if
fresh air is not replacing what is in the room, the level rises. That makes it a good
stand in for ventilation, which is otherwise invisible.
Useful reference points: outdoor air sits around 400 to 420 ppm, so that is your floor.
A room with air genuinely moving through it tends to stay below 800 ppm. Somewhere above
1000 to 1500 ppm you are mostly rebreathing the room's own air.
Watch it change, not just the number
The refresh rate is the part people underuse. Because the reading updates every second,
you can open a window or a door and watch what happens. Some rooms drop hundreds of ppm
in a couple of minutes. Others barely move, which tells you the airflow is not where you
assumed it was.
That single test is worth more than any absolute reading, because it tells you whether
the fix you were planning will actually work in that room.
Where to put it
Put it at head height, away from a window and away from a doorway. Sitting it on a windowsill
measures the outside air coming in, which reads reassuringly low and tells you nothing about
the room. Keep it away from where someone is breathing directly onto it too, which spikes the
reading.
For a room in constant use, leave it plugged in and let the alarm do the work.
What it is not
This is a ventilation gauge. It does not detect carbon monoxide, smoke, or particulates,
and it is not a medical or safety device. If you need a carbon monoxide alarm, fit a proper
CO alarm alongside it. The two measure different gases and one cannot substitute for the other.
Tell us the room, how many people use it and what you are trying to find out, and we will tell you whether this is the one that fits. Free delivery across the United Kingdom on orders of £50 or more.
CO2 Meter sold by CO2 Company UK at co2monitor.uk, at GBP 89.
A palm sized 3 in 1 air quality monitor that measures carbon dioxide from 400 to
5000 ppm, temperature from 33 to 150°F and humidity from 0 to 99% RH, showing all
three on one full colour backlit screen and refreshing every second. It has an
audible alarm that triggers when CO2 passes the threshold, so it can monitor a
room unattended. Powered by a 1200 mAh rechargeable battery charged over Type-C,
and it continues reading while charging. Weighs 108 g, stands on a desk or hangs
from slots on the back. Carbon dioxide is used here as an indicator of
VENTILATION, not as a health measurement: outdoor air is roughly 400 to 420 ppm,
a well ventilated room typically stays below 800 ppm, and readings above about
1000 to 1500 ppm indicate a room is recycling its own air. Bought for classrooms,
offices, meeting rooms, workshops, bedrooms and greenhouses. The larger sibling
product is the Jumbo CO2 Monitor, a wall mounted display covering the same
measurements. No accuracy tolerance or calibration figure is published for this
model, so none is claimed. Delivery is free across the United Kingdom on orders of £50 or more. Below £50 the only method offered is Express Delivery at £22, and Express Delivery is also available on any order at £22 as a paid delivery option. Orders arrive in 5 to 7 days after a 24 to 48 hour handling time.
