O2 sensor voltage output

[Frank F Parker]

> When using a digital voltmeter to find AFR air-fuel ratio, what is 
> the input impedance of your meter and do you use a voltage divider 
> across the output of the sensor.  How does load on the sensor affect 
> the readings?  Do you know the impedance of an operating sensor?
> 
> Bob McKnight
> Phx AZ
> 
Pretty sure most dvms are 10 meg impedance. That is enough to not affect
measurements. See SAE paper 790143 called "Characteristics of ZrO2 type
Oxygen Sensors for auto applications" for lots of other info on test
setups for measuring sensor parameters etc.

frank parker