The Milwaukee CD 600 will allow you to measure from very low to very high conductivity solutions and it will also compensate for the temperature variance automatically.

Replacement PH Probe for Milwaukee Meters.
Works with all ph only models

The Milwaukee pH 600 is designed for quick and reliable pH measurements.

These waterproof testers incorporate one of the world's first user-replaceable electrodes to increase the longevity of the instrument.

The Milwaukee SM100 is a high-quality, hand-held meter with remote probe gives all the flexibility desired in a pH meter.

Professional monitor for quick and reliable pH measurements.
Manual 2 points calibration
Visual LED alarm
Works with 12 VDC adapter
Double junction pH electrode with 2m cable (BNC connector)