Use and maintenance of conductive electrodes
1. Use of conductive electrodes
(1) To ensure the measurement accuracy of the conductivity instrument, if necessary, the electrode constant should be recalibrated with the conductivity instrument before use. At the same time, the conductivity electrode constant should be calibrated regularly. If there is a significant error, the conductivity electrode should be replaced in a timely manner.
(2) When measuring high-purity water, pollution should be avoided, the constant of the conductivity electrode should be correctly selected, and it is best to use a sealed and flowing measurement method. Otherwise, its conductivity value will quickly increase because carbon dioxide in the air dissolves into high-purity water and becomes a conductive carbonate ion, which affects the measured value.
(3) To ensure measurement accuracy, the conductivity electrode should be rinsed twice with deionized water (or distilled water) less than 0.5us/cm before use, and then rinsed with the tested sample before measurement.
(4) The value displayed by the instrument after measurement has been converted to the measured value. If no compensation is needed, remove the temperature electrode from the instrument display, and the measured value is the conductivity value of the solution at that time.
2. Maintenance of conductive electrodes
(1) Storage of conductive electrodes
Bright platinum electrodes and platinum black plated electrodes (not used for a long time) are generally stored in a dry place, but platinum black plated electrodes must be stored in distilled water for several hours before use. Frequently used platinum black plated electrodes can be stored in distilled water.
(2) Cleaning of conductive electrodes
① Organic contamination on the electrode can be cleaned with warm water containing detergent, or it can be cleaned with alcohol.
② It is best to clean calcium and magnesium precipitates with 10% citric acid.
③ Bright platinum electrodes can be mechanically cleaned with a soft brush, but there should be no scratches on the surface of the electrode. Hard objects such as screwdrivers should never be used to remove the electrode surface, and special attention should be paid even when cleaning with a soft brush.
④ For platinum electrodes coated with platinum black, chemical cleaning can only be used. Cleaning with a soft brush will damage the coating (platinum black) on the electrode surface.
