need to find most economical way to monitor CO2

Hey guys I am automating my grow room using an allen bradley 5/04 plc. I know there are many high priced solutions to monitor co2 ppm by using a 4-20ma output of the device. What im trying to find is if anyone knows an economical solution. The key is I need to be able to read the analog voltage and convert it to ppm. I am looking to find any solutions under $200. I ideally would like to find something around $100 or less. Seems that co2 control is the most expensive part of growing. We need to find a good cheap solution for this. Help please. All comments are good comments!!!

Get a very young canary and train it to push a button over and over all day as long as the lights are on that blasts a hit of co2. He'll pass out if he gives too much most likey, but if he dies you can try again with another.

Cheap and simple.

this module will either output a signal that can close a relay to disperse gas and can output an analog voltage proportional to co2 ppm you cans et high and low threshold. Price is around $70. This is all you need plus relay to control co2 in an automated grow. I will feed the analog voltage into my PLC scale the voltage and have a readable ppm of co2. Here is links.
http://www.figaro.co.jp/en/pdf/CO2GasSensorModuleCDM4160.pdf


http://www.kofriel.com/itp/blog/wp-content/uploads/2008/02/price-01_08-usa.pdf

Many canaries might produce enough CO2 and will sing to the plants which further promotes growth.

Sounds scientific

The Figaro is inexpensive and will solve your problem. However it is electrochemical, which means it is slower to react and has a 2 year lifespan.

For $99 you can get a dual-beam self-calibrating infrared sensor that does the same thing, reacts quickly to changes in CO2, with 15 year lifespan.

http://www.co2meter.com/collections/co2-sensors

Either way you'll have fun with a soldering iron. Cool project.

ohhhhhhhhh boy that baby is nice!!!! and right at my target value of 99 duckets. thanks for the post. If any other ideas are out there in some potheads scientific mind pleas let me know.

+/- 20%? At the ideal 1500ppm thats a 1200-1800 swing of accuracy.

danksmoker77 said:

this module will either output a signal that can close a relay to disperse gas and can output an analog voltage proportional to co2 ppm you cans et high and low threshold. Price is around $70. This is all you need plus relay to control co2 in an automated grow. I will feed the analog voltage into my PLC scale the voltage and have a readable ppm of co2. Here is links.
http://www.figaro.co.jp/en/pdf/CO2GasSensorModuleCDM4160.pdf


http://www.kofriel.com/itp/blog/wp-content/uploads/2008/02/price-01_08-usa.pdf

Click to expand...

big bud not sure where u checked but my data sheet says +/- 50ppm did alot of research on this its an oem part used in alot of wall mount meters. most companies only sell mulitples of them but co2meter.com will sell onsies. it seems to be a good module. i placed my order so ill let you know how it works!!!

First datasheet you posted, second page. +/ 20% full scale range.

danksmoker77 said:

big bud not sure where u checked but my data sheet says +/- 50ppm did alot of research on this its an oem part used in alot of wall mount meters. most companies only sell mulitples of them but co2meter.com will sell onsies. it seems to be a good module. i placed my order so ill let you know how it works!!!

Click to expand...