Printable Version | Subscribe | Add to Favourites
New Topic New Poll New Reply
Author: Subject: Super cheap CO meter
theconrodkid

posted on 10/11/15 at 07:53 PM Reply With Quote
Super cheap CO meter

after lots of messing around i have devised a super cheap CO meter,ok not 100% accurate but near enough,what you expect for £4 ?.
ordered one similar to this 85C1-V Class 2.5 Voltmeter DC 0-5 Volt Wht Panel Meter

mine is 0-1 volt,connect it to earth and output of lambda sensor and watch the vlotage.
0.45 is 14.7-1 or near enough,up to 1 v is rich,lower is lean so you can twiddle your megasquirt etc and have an idea where you are going .





who cares who wins
pass the pork pies

View User's Profile E-Mail User View All Posts By User U2U Member
MikeRJ

posted on 10/11/15 at 09:48 PM Reply With Quote
A moving coil meter will almost certainly present too much load to an oxygen sensor, they have very high output impedance. Using a digital multimeter would work ok, but narrow band sensors are pretty hopeless for setting anything other than a stoichiometric mixture.
View User's Profile View All Posts By User U2U Member
theconrodkid

posted on 11/11/15 at 09:06 AM Reply With Quote
i had thought about using a digital meter but watching a needle seemed a lot easier than constantly changing numbers.
anyhow,as i said it works as a guide





who cares who wins
pass the pork pies

View User's Profile E-Mail User View All Posts By User U2U Member
DW100

posted on 11/11/15 at 09:21 AM Reply With Quote
Narrow band sensors tend to switch about the stoichiometric point and really only show rich or weak. They do not give a linear output relative to air / fuel ratio. This is why if you look at a lambda waveform from a normal tin top the voltage oscillates between around 200mv and 800mv with the ecu trying to average the readings.

I did build a device years ago with a LED bargraph but gave up as it didn't really gives meaningful readings.

View User's Profile View All Posts By User U2U Member

New Topic New Poll New Reply


go to top






Website design and SEO by Studio Montage

All content © 2001-16 LocostBuilders. Reproduction prohibited
Opinions expressed in public posts are those of the author and do not necessarily represent
the views of other users or any member of the LocostBuilders team.
Running XMB 1.8 Partagium [© 2002 XMB Group] on Apache under CentOS Linux
Founded, built and operated by ChrisW.