Pocket meters used for EC and pH measurements. pH meter comes with pH 4 and 7 calibration solutions. I use a 342 (533 uS/cm) ppm calibration solution to check the EC meter (it is factory calibrated). More details on the pH meter here.
I routinely measure electrical conductivity on watercourses that I encounter, and pH of some of them. The EC measurement are made with a pocket HM Digital Aquapro Water Tester AP-2 which measures electrical conductivity and temperature.*
*Available at amazon.ca (C$32.59 on Apr13, 2026)
It is inserted directly in the water or a sample is placed in a jar and the measurement made immediately.
I purchased this piece of equipment in June of 2017 specifically for this purpose (cost ~$30). It was factory calibrated with a 700 µS standard. According to the manual, readings are temperature compensated, so they are Specific Conductance values (Electrical Conductivity at 25 deg C). I had no technical issues using it and measurements on a reference sample of tap water were consistent.
I purchased a second Aquapro Water Tester in July of 2020 and gave to a Sandy Lake Volunteer for use in monthly monitoring. In an in-field comparison of the two meters on Oct 2, 2020, the two meters gave identical results. A 342 ppm NaCl standard from HMDigital read 699-704 uS/cm, Temp 19.4oC (Mar 2, 2021); the ppm 500 scale valueis 684 uS/cm. (I assume the standard is HM Digital’s 700 uS/cm standard they use to factory calibrate these instruments.) View Manual for this instrument.
As of April 2026, both of these instruments are still functioning without issue.
– david p