Best value sensors for Carbon Monoxide and Smoke

[alexsh1]

This sensor is expensive, but it is the most precise. Yes, there are disadvantages like the power (working current: 50mA mean value of the peak value of 100mA) and it is pre-mounted as you said, but this is all about precision here. They are available for $27+ on Aliexpress.

@Samuel235 said:

@alexsh1, If i'm honest I'm only interested in knowing if there is smoke present in the air so this might work. However, they seem to come pre-mounted to a board and they are no cheaper than anything else i have been looking at. Still seems hard to get a hold of too.

[alexsh1]

http://www.aliexpress.com/item/FREE-SHIPPING-MH-Z14-Infrared-carbon-dioxide-sensor-module-Analog-output-environment-monitoring/32599614226.html?spm=2114.30010308.3.12.2bmxjq&ws_ab_test=searchweb201556_2,searchweb201602_5_10034_10033_507_10032_508_10020_10017_10005_10006_10021_10022_401_10018_10019,searchweb201603_2&btsid=d825bfa5-f2ac-46c3-8d40-7a3f66083d1f

[Samuel235]

@alexsh1, i must admit i like their properties but i'm not sure if thats too extreme. Maybe thats bumping the price for precision thats not needed that close. If i wanted to know the ppm exactly of the air i would get them right now. But i just care if the ppm touches a certain point roughly to then set the alarm status for the home automation controller.

[scalz]

@samuel235 I have made some attempts with some professional supplier for some exotic ics, and even if we own a company (with my dad) they were not interested..by opensource hardware! Ok for samples, but they asked me if I wanted to be incubated! Sure if I was working in iot, kickstarter etc could tempt me a lot but it's a lot of time that I don't have, plus I'm alone on my projects...
So it Seems they are more interested by big commercial batchs than our humble maker community. Not sure they like opensource schematics...or maybe for their chick :) Too bad but I was not surprised. The only thing I thought then would be to ask our chinese friend for help.

I hope you will have good news, just my story, btw these are nice sensors :)

[epierre]

@micah said:

Alarm clock (with remote access, personalized wake-up midi songs, manual and auto snooze i.e.: if you don't get out of bed it rings again)
Wake-up light

MH-Z14 is working fdine for me over 2 years... no fault, always good values out of it, I can only recomment it ;-)

[alexsh1]

@epierre

The only downside is (1) price and (2) it cannot be used with batteries

[Samuel235]

@alexsh1 said:

@epierre

The only downside is (1) price and (2) it cannot be used with batteries

For these factors alone, the Figaro looks very appetizing.