When encountering DO measurement problems …
This can be checked with a pH simulator or using a pH electrode and buffers to see whether the input functions correctly. If required, check the temperature input with a Pt1000 sensor. If not available, use an electronic resistor with a value between 1000 Ohm (=0°C) and 1300 Ohm (almost 78°C).
1. The condition of the electrode's parts:
2. Some tests of the electrode with an Ohm meter:
3. When 1. and 2. are found to be OK. The electrode should be reassembled. Watch very carefully for the correct placement of membrane, O-ring and membrane cap. After reassembling, filled with the electrolyte, a Voltage should measured at the BNC contacts. While polarising, this Voltage will be decreasing and will end with a value between 30 and 90 milliVolt at room temperature. Value? ……. mV