Inexpensive co2 sensors
Hi ,
Does anyone know where I can get a decent CO2 sensor for a relatively
good price ?
Thanks,
Vince
Does anyone know where I can get a decent CO2 sensor for a relatively
good price ?
Thanks,
Vince
Comments
>Hi ,
>
>Does anyone know where I can get a decent CO2 sensor for a relatively
>good price ?
>
>Thanks,
>
>Vince
>
>Vince -
What's the application - airborne, dissolved, etc. and how much room do you
have to work with ?
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Vince
--- In basicstamps@y..., Bruce Bates <bvbates@u...> wrote:
> At 07:56 PM 8/12/2002 +0000, you wrote:
> >Hi ,
> >
> >Does anyone know where I can get a decent CO2 sensor for a
relatively
> >good price ?
> >
> >Thanks,
> >
> >Vince
> >
> >Vince -
>
> What's the application - airborne, dissolved, etc. and how much
room do you
> have to work with ?
>
> >To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@y...
> >from the same email address that you subscribed. Text in the
Subject and
> >Body of the message will be ignored.
> >
> >
> >Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
>Does anyone know where I can get a decent CO2 sensor for a relatively good
>price?
>The application is airborne...mostly for green houses.
http://www.google.com/search?&q=%22carbon+dioxide%22+sensor
returns a load of results.
I've had some industrial experience in sensing CO2 at levels present in the
atmosphere and have never found a "cheap" solution.
Bear in mind a sensor is only a start. You need a pump to move your air
sample thru the sensor, a good (!!) filter to eliminate dust getting into
the sensor, and you must assure a noncondensing atmosphere in the
sensor. Vibrating aquarium pumps placed on the inlet side work well, but
check airflow periodically and be prepared to replace or rebuild the pump
when the rubber cups wear and crack. Also bear in mind that sucking air
thru the wall of a greenhouse to a sensor just outside can result in
cooling it enough to cause condensation. You need to keep all parts of the
system inside the environment being measured, or else provide a
condensation trap before the sensor. Water (or dust) in the sensor is a
really big No-No.
Also bear in mind when selecting a sensor that the typical atmospheric
concentration for CO2 is 370 ppm and select a sensor (or complete
instrument) that works and gives acceptable accuracy and resolution in this
range. You'll find instruments meant for high range measurements around
2.5% (25,000 ppm) to be useless - cheaper, but useless for resolving small
changes in normal atmospheric levels.
Your own breath will have a very strong effect on the reading if you exhale
anywhere near the intake. I advise placing the display unit 5 - 10 feet
(downwind if applicable) from the air intake.
Jim H