Circuit Specialists Inc.

[neil.poersch at mts.mb.ca]

Orin,
                                                                 
                                                                 
                                                                 


>
Are the Circuit Specialists displays backlit?  Most of the Digikey ones
are as I recall.<

Circuit Specialists' units are not backlit.  Digikey has both types,
backlit being more expensive, non-backlit still much, much more than
Circuit Specialists.




>
I'd check how frequently the meter updates.  Usually it's only a couple
of times a second.  You would want a low pass filter with a cutoff of
around 1Hz before the meter to produce sensible results!  You can see
the O2 signal swing back and forth on LED type displays - if that's what
you want of course.<
The Circuit Specialists unit is 2 - 3 times per second, same as the others.
I can add a low pass filter if needed but it may not be.  Last summer I
used my DVM directly to read the output of the O2 sensor without any
problem. The typical LED unit has a resolution of 0.1 volts while I was
using my DVM set to 0.01 resolution.  I found that extra decimal point of
resolution to be very helpful. I used it to set the jetting of the new
carbs on my motorcycle and it was MUCH better than doing plug chops. I am
always doing something to the motor so I want to free up my DVM and install
a permanent readout to watch what is going on.  You would be surprised what
you see when you monitor on a day-to-day basis as compared to a one-shot
tuning effort.

Neil