Low Conductivity Water
Pure water is very low in ionic strength and therefore it is very difficult to obtain a stable reading with a pH electrode. This is due to the reference junction. Inside a standard electrode is a highly ionic solution of potassium chloride. When such an electrode is placed in a pure water sample a potential difference can be created across the junction. This leads to unstable and drifting readings.
The polymer filled K-Series range from Thermo Electron is the ideal solution. The reference cell is silver/silver chloride, and the body of the electrode is filled with a substituted polymer. This eliminates the need for a ceramic junction as there are simply two holes in the outer body. This greatly reduces the potentials created across a junction allowing for more stable and virtually drift free operation.
"The most important criteria for us when buying a pH electrode is that it is fast reacting and produces stable and reliable results. We have found this electrode to be faster and more stable, than our old standard type, in both our buffers and our samples," said one customer who uses this type of electrode.
Electrode Specification
pH Range
0 - 14 (2 - 12 optimum)
Temperature Range
0 - 40ºC
Dimensions
120mm long x 12mm diameter
Thermo Electron manufactures and supplies all electrodes with 1m cable terminating in BNC. Should other termination or dimensional variation be required please do not hesitate to contact us on 01337 828871 and our technical team will be able to answer your questions.
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