I've read on Steve B site http://www.peachparts.com/Wikka/EngineControls that when measuring the O2 output with a scope (I hope to do this Saturday) the duty cycle is the ratio of low voltage to high voltage. But this is contradictory to the duty cycle definition in the electronics industry. Where it's always high to low.

ie Steve shows a nice piccy of a scope (Fig 1) showing 30%, but clearly this should be 70% in my book. Is this due to the electronics inverting the output before presenting it to the X11 connector?

I'm pretty sure that O2 sensors themselves o/p a voltage 0.1-0.9V (approx) with the output increasing with detected O2?

Could someone help and clear my confusion..

Cheers
Lea

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'93 R129 500SL-32
'89 190E 2.6 - sold in 2002

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