Zirconia O2 sensor alternate modes of operation

Zack zubenubi at inetport.com
Sun Feb 22 02:25:51 GMT 1998


All,

I've been reading some SAE papers about O2 sensors, and a couple of them
mention biasing a zirconia-type sensor with a low voltage and measuring the
output current, rather than measuring the open circuit voltage as is
usually done.
	The response of the sensor to A/F ratio in this regime seems much more
linear, and thus more suitable to measuring A/F than the usual open circuit
method (which works extremely well for maintaining lambda = 1 but is not
very good for measuring lambda at points above or below).
	My question is this, none of these articles make any specific mention of
what type of sensor is being used, though they're mostly written by people
working for research labs of large corporations, so I'm assuming they're
probably using one-off probes that they've designed with an eye towards
this method of operation. 
	So... my question is, for anyone who might now, can any garden variety
heated zirconia sensor be used in this manner??  Will it be damaged by the
current (small but not negligible) that flows through the zirconia
electrolyte when used like this?  What would the usable measurement range
be?

-Zack



More information about the Diy_efi mailing list