RE: [PSUBS-MAILIST] Life Support Revisited/CO2 monitor

["Alec Smyth" <Asmyth@changepoint.com>]

William,

That sounds really interesting, but when I read the manual I was left
wondering about the interface protocol. Did it by any chance come with
more detailed instructions than what is in the 4 page online manual?
>From reading that, it isn't obvious to me how I would tell it to take a
reading, or where I would measure the output. Are you planning on
interfacing this to something else, or were you going to use the
optional readout?

Thanks,

Alec

-----Original Message-----
From: William Alford [mailto:walford@dbtech.net] 
Sent: Wednesday, August 06, 2003 10:51 AM
To: personal_submersibles@psubs.org
Subject: RE: [PSUBS-MAILIST] Life Support Revisited/CO2 monitor

At 09:35 AM 8/6/2003 -0400, you wrote:

>On TI's catalog I found the following:
>"Sensors & Controls gas sensors are presently comprised of two families
>of CO2 sensors: The 4GS -- typically in indoor air quality applications
>for measuring concentrations up to 5000 parts per million 

take at look at these. I obtained one of these for evaluation but
haven't
tested it out yet--
http://www.dcs-inc.net/m305.htm, around $165 I think.

the linear measurement output is available as an analog voltage or a
pulse-width modulated digital signal. Analog output is 0.1-3v and range
is to
2000ppm CO2 with resolution of 10ppm and accuracy +/- 5%. I believe it
may be
available in 5K ppm as well.

William Alford