jasen wrote in :


what's the output impedance of the pH sensor.
is the output ground referenced, isolated, or differential?

Bye.
Jasen


Oops, the ADC input tolerance is -0.3V, not -0.5. I'll look for germanium
diodes though! -0.2V would work.

The output impedence is somewhere around 500K-1Meg, which is why I'm using
a 10 teraohm input impedenace op-amp. The sensor ground is simple connected
to circuit ground.