Apera Instruments PC 823-B Portable pH/EC/TDS/Temp Meter

Apera Instruments Value Series PH850-WW Portable pH Meter Kit Wastewater AI5531

Portable Multi-Parameter Meter Kit (pH/Conductivity/TDS/Temp.)

APERA Instruments SX721 pH/ORP/Conductivity/TDS ++ Portable Meter Kit

Portable pH/Conductivity Meter

Apera Instruments PH60 Waterproof pH Pocket Tester Kit With Carrying Case

Apera Instruments Premium Series PH8500 Portable Handheld pH Meter Kit

Thermo Scientific Orion Star A325 Benchtop pH/Conductivity Meter