Supco IAQ50 CO2 Carbon Dioxide Meter Indoor Air Quality Monitor Temperature and Humidity With Dew Point, Wet Bulb - Desktop or Wall Mounting

Useful. Add a switch is better.

Very fast tracking of CO2 levels. EXCELLENT product. Examples I discovered: As soon as you enter a room with the monitor, the levels start to rise from your own breath. If you want uncontaminated data of the baseline level of a room's ventilation, you have to set the sensor in the UN-occupied room and IMMEDIATELY leave the room, preferably closing the door behind you, wait a few minutes, then re-enter the room and check the reading immediately before it goes up. I found my breathing raised my home-office or my bedroom by about 300 PPM after the room had been vacant for about 8 hours. This is due to no mechanical air flow fan moving air in the house. For best quality/healthy sleep levels, I highly advise sleeping with your bedroom door open. If two folks are sleeping the the same bedroom with the door closed, you most surely are above the unhealthy 1100 PPM and may be suffering from lack of motivation, tired days, and possibly heart murmurs. Everyone should have one of these in the house. Everyone should also have an ERV (Energy Recovery Ventilator) which brings in fresh air from outside. GOOGLE it.

It is okay but the alarm tends to go off easily, if two people are sleeping with the door closed and window is not open. I use it to get an understanding of ventilation but not to leave it plugged it.

I bought this because I installed an unvented gas heater in my basement to heat my office area.CO2 meter arrived a few days before plumber arrived to hook up heater, so I plugged it in to get an idea of baseline CO2 levels without this new heater. Of course, humans exhale carbon dioxide. Meter is about 5 ft from my body, at 9 o'clock when I am facing 12 o'clock at my desk. When I sat down, meter read 451 parts per million. After an hour or so it read 568 ppm, just from me breathing. When two plumbers were here to hook up heater to gas line, 3 of us were within 10 feet of the meter. Reading at start was 465. Reading with 3 of us exhaling for an hour was 760.Don't know how accurate it is, but it sure is sensitive. Easy to operate. Alarm can be set at different CO2 levels. A little pricy compared to carbon monoxide meters, but well worth the money with an unvented gas heater 6 ft behind me. BTW, carbon monoxide (CO) meter is at 3 o'clock when I am facing 12 o'clock. CO2 to my left and CO to the right. Can't be too careful with unvented combustion heaters, IMO.

Performs properly BUT every few days the alarm sounds and it gives a false reading of 2500+ for a few seconds. It ruins the MAX feature. If they can fix this flaw I would rate it 4/5.

I purchased this to monitor CO2 levels in a small grow area and it seems to work very well. It is quite sensitive and you will definitely notice a change if you are breathing near it. After reading the manual the alarm was quite easy to set although it does use some useless menu names like "P1.0" to describe the upper alarm limit and so on. The only problem I have noticed is that you have to push the buttons quite hard to activate them. You can press a button with a normal amount of force and you will feel it go down and hear a click but nothing will happen on the device unless you mash it harder. Mine is still brand new so perhaps this will loosen up slightly but I doubt it. Bottom line this monitor is cheap and works great.

the RS232 connection does not work and it is active in the specifications sheetMy any one explain me it please?

Excellent quality, works flawlessly and is easy to use. No instructions necessary. I've been using it in my garden for 5 months now and it has had no issues at all. I enrich my garden atmosphere co2 from the normal 350ppm to around 1200ppm. Sometimes I treat for pests by flooding with co2 and this meter has an alarm you can set from 0 to 9999 ppm. I open a tank of co2 and walk out the door, I only return after the alarm has turned off (i keep it set to alarm at 5000 ppm and alarm turns off once it gets below 2000ppm.)