After a web-search, it seems ISAs (Ionic Strength Adjusters) are offered commercially to assist pH electrode/probe measurements. Presumably meant to increase conductivity (without affecting pH significantly) to make a reading more stable/accurate. Commonly KCl, presumably since it's present already for electrode fill/storage.
Would increasing the ionic strength, of say tap water, with KCl or NaCl also help the rather different mechanism of measurement by pH test strip color change be more accurate?
(Again from web-searching, see there are "low-ion" pH test strips offered for sale, but cannot tell from the description how they work - except possibly they may have to be read while submerged into a provided solution.)
