TY will check these outSome of Milwaukee’s pH probes are compatible with Apex. There’s a few that have the same style connection, but others that don’t. As far as which probe to get I’d head over to Milwaukee’s website and get a double junction lab grade probe. I believe these two below will work. Double check it before you buy.
Milwaukee SE220 Lab Grade Double Junction pH Probe
Milwaukee is your best source for pH, TDS, ORP testers, meters, monitors and controllers. Upgrade to Milwaukee for affordable, high performance digital measurement.milwaukeeinstruments.com
Milwaukee MA911B/2 Lab Grade Double Junction pH Electrode with Extended Cable
Milwaukee is your best source for pH, TDS, ORP testers, meters, monitors and controllers. Upgrade to Milwaukee for affordable, high performance digital measurement.milwaukeeinstruments.com