RE: Gunson CO2 meters, Air intake sensor

["Buchholz, Steven" <Steven.Buchholz@kla-tencor.com>]

> I have opened a Gunson, and it appears that it uses a heated wire 
> bridge that compares the intake gas with a closed off reference. It 
> has to warm up for abt. 15 mins before measuring.
> 
I understand the Gunson uses a hot wire technique similar to that used
for airflow sensors on the newer Motronic-equipped cars.  It runs a
known flow rate of air past the wire, and infers the CO2 content based
upon how much cooling of the wire occurs.  My understanding is that it
is a very slow process

> Measuring mixture setting whilst driving?
> 
> That brings up a question, what would be a good way of measuring 
> mixture setting whilst driving? (Our cars were not equipped with a
> lambda 
> sensor and mixture setting makes a huge difference in the car's
> performance.) 
> Charles Probst talks about measuring gas temperature in the 
> exhaust?
> 
Nobody's stopping you from mounting an OXS in your exhaust tract and
hooking it up to a CO meter though.  If you used a heated OXS you might
even be able to make a portable unit that attached to the exhaust pipe
or CO tap tube ... if you have one ...

> Air intake sensor 
> 
> You might want to solder spade connectors onto the wires.
> 
I believe that the sensor is hardwired in there for a purpose.  I'd
recommend that if you do add some sort of connector that it have gold
plated contacts to minimize the change in resistance.  

VdT!
Steve Buchholz
San Jose, CA (USA)