O2 sensors

["Matthew J Reinhart" <matthew_j_reinhart@spacemail.jhuapl.edu>]

                       Subject:                               Time:9:59 AM
  OFFICE MEMO          O2 sensors                             Date:11/20/95
Dave Head wrote offering to post O2 sensor bench testing procedures.  I would
like to see these.  Also, the universal one sold by GPR for $69 is made by
Bosch and is identical to the factory installed part except for the wiring
harness (it works fine in my application).  Where did you find one for only
$45, is it Bosch?

RDH wrote:  the 02 sensor is a "current source" (hence the need for a "high
impedence" DVM/etc to measure it).  Let's clarify this a little more.  Some
sources are constant voltage (over a limited range of current), while some
are constant current (over a limited range of voltage).  The O2 sensor is a
constant voltage source that happens to not have much total current available
from it.  Hence it is measured with a VOLTmeter.  A high impedance voltmeter
is needed to prevent loading down the sensor (ie. trying to draw more current
than it can supply).

  Matt Reinhart  '87 4000CS