I have made a 10 LED bar graph air/fuel meter. I need to know how to test it's accuracy.
any ideas?

 

Hmm I have no idea. Why not just spend the $30 on a all ready calibrated one?

 

I guess you would have to rig up a 1.5v battery with different resistors. and check your readings with a voltmeter.

 

Ya, hook up a couple AA batteries together with a variable potentiometer... There is a chart I have that shows what voltage the o2 sensor sends out at different AF ratios.....
Just use those values..
Try an autometer.com, under the tech section, it might be there.
I posted it earlier, it's here somewhere.... I am not at home though.

 

I was worried about variables. I'm am sure this thing is close, I just want to know how close with the way I have it set up. Meaning every inch I have the connection away from the sensor is going to ghange the reading. the sensor may not be up to par, the meter could be way off and I won't know it. There are too many variables that could happen to change the accuracy of the unit. plus it only cost me $8 to build this from Radio Shack. that is total. Because I already had the solder and iron.

 

ordinary O2 sensors can't be made accurate for readings even slightly away from the 14.7 ratio.
That's why some of use are building the wide band o2 meter kit, that thing will be useful for power tuning, etc.

-Les

 

tell me more les.

 

Put a digital meter on the o2 sensor output and compare the readings. Also, ask Les about the wideband.

 

See here: http://www.techedge.com.au/vehicle/wbo2/default.htm

I goy my kit , I'm 3/4 done with it. I just have to test the 2nd half, before I put the sensor on it. They also sell pre made kits. See the web page for info.

-Les