In What is the purpose of this op amp? you see my interested circuit.
The diagram above shows a single pH measurement "channel".
U1 sets a reference voltage of Vout_LM4140A/2, and U2 measures the voltage outut of the pH probe relative to the reference voltage.
I wish to add a second independent pH probe.
I could add two new amplifiers say U1 as reference and U2B for measurement.
However, is there any reason why I should not add a U2B but share the existing reference source from U1 for both probes?
- I measure output of u2 in single ended mode. There is no problem with one electrode (for example pH).
But i need to measure different electrodes using same common reference in same time (in here reference is taken by u1). If i connect another electrode which have same characteristics with pH electrode and works with same reference to new lmp7721 (as u3) like u2, is it correct?