Wide Range O2 sensors

[Jennifer and Brock Fraser]

Hello,

I'm sure this topic has been discussed many times over, but I've been off
the list for 6 months or so and am just now returning.  

Due mainly to the fact that Honda and a few others (we use them on Natural
Gas engines at Deere) are making sales volumes increase, the wide range (5
or 6 wire) o2 sensor sold by NGK/NTK is coming down in price.

Does anyone know of any affordable devices (even an oscilloscope) that can
display or convert the output of this sensor into some meaningful value,
other than the spendy converter box sold by NGK exclusively for the sensor?

Absolute precision isn't required-  I'd just like something wide range that
is at least repeatable.  I know that these sensors are individually cal'ed
- either at the sensor with a pig-tail resistor or something, or as a
trimming value at the meter that is reading the output.  

>From experience, if the cal is wrong for a particular sensor, you aren't
that far off... (Alleviating the need to cal if you can live with some
error if you are more concerned with repeatability)

Thanks,
Brock