Wideband Tailpipe Sniffer Tube Design - Input Wanted
Posted: Wed Nov 25, 2015 9:52 am
For a long time I've wanted to build a general purpose tool for measuring the exhaust mixture of any random car that I felt the need to. Well, I just ordered the wideband controller, display, and sensor to do just that. So now I need to design and build the rear end of this arrangement, and thought I'd seek your input, whoever y'all are.
Requirements:
Innovate has one that seems extreme, but might be the minimum required:
http://stuff.fredcooke.com/innovate-clamp-highres.jpg
FAST have one that seems insufficient:
http://www.fuelairspark.com/fas/ez-clam ... t-kithtml/
http://www.jegs.com/p/FAST/FAST-EZ-Clam ... 8/10002/-1
My thoughts? Innovate's one puts the sensor in quite a laggy spot. But perhaps that's to guard against water droplets having a direct path to the ceramic element? Optional rubber cap for the screw clamp would be nice. Lower diameter is better than higher, and something bigger will allow a higher air speed through the centre past the sensor. Maybe 25mm or 30mm ID or something like that for optimal sensor-pipe geometry? But if you want to dump it out up stream rather than down stream, 2 times 25mm is getting pretty big. Not much more to say right now.
Any and all input welcome! Post away! :-)
Fred.
Requirements:
- Effectively guard against reversion
- Clamp to the outside of the tube in a non-damaging way
- Fit relatively small pipes as well as larger ones with equal efficacy
Innovate has one that seems extreme, but might be the minimum required:
http://stuff.fredcooke.com/innovate-clamp-highres.jpg
FAST have one that seems insufficient:
http://www.fuelairspark.com/fas/ez-clam ... t-kithtml/
http://www.jegs.com/p/FAST/FAST-EZ-Clam ... 8/10002/-1
My thoughts? Innovate's one puts the sensor in quite a laggy spot. But perhaps that's to guard against water droplets having a direct path to the ceramic element? Optional rubber cap for the screw clamp would be nice. Lower diameter is better than higher, and something bigger will allow a higher air speed through the centre past the sensor. Maybe 25mm or 30mm ID or something like that for optimal sensor-pipe geometry? But if you want to dump it out up stream rather than down stream, 2 times 25mm is getting pretty big. Not much more to say right now.
Any and all input welcome! Post away! :-)
Fred.