What factors are important in designing pH electrodes and metallic electrodes?

[NSK8700]

I have not searched enough/researched, but my immediate need is to clarify the following in the context of pH electrodes, metallic electrodes and conductivity cells, particularly as regards the way they are conceived/ designed, [WARNING] my queries may be naive [WARNING]:
(1a) Often a vendor mention's pH electrodes as a "COMBINED pH electrode", what could/ does the manufacturer imply by the term "COMBINED" ? (1b) What limits the maximum pH scale to 14 (max) (1c) What typically delimits the electrode construct dimensions (2) In a particular construct what contributes to the Resistivity of such pH electrodes [typically 200-300MegaOhm] What determines the operating temperature specification of such electrodes and what is rationale for using 'KCl' as the reference electrolyte.(3) On what basis is the choice of electrode metal in metallic electrodes done, vis-a-vis, Platinum,Gold,Silver,Antimony,Tungsten electrodes,is there a reference chart as to their appropriate utilization/ applications.(4)What factors enhance or influence precision in such electrodes and the typical potential I would also appreciate some novel or unusually applied experiments that could qualify for Junior or Senior college project(s).

 

[Borek]

Your queries are not naive, but you are naive thinking we will answer them all. We can explain details once you will try to understand them by yourself.

Check out www.ph-meter.info - that should be a good starting point.

 

[NSK8700]

Borek : Thanks, I will review them...BTW,are you (among) the principal(s) @ www.chembuddy.com/

 

[Borek]

I AM ChemBuddy.

 

[NSK8700]

Borek: (1)Have you come across Hg/HgO with KOH electrode for Oxygen evolution studies and do you have comments or suggestions to source the same from.(2) In the context of defined measuring systems we have for O2,chemical or zirconia, How can one analyze and conclude about the "best" measuring system for CO2 gas ?