This standard specifies the method for quantifying dissolved oxygen in water using the electrochemical probe method. Here, the electrochemical probe method is a method in which dissolved oxygen is separated from a sample using a gas permeable diaphragm and measured using an electrochemical cell. Depending on the type of equipment used, it is possible to display oxygen concentration (mg/l), saturation percentage (% dissolved oxygen), or both. It is possible to measure from 0 to 100% saturation, and most devices can measure supersaturation of 100% or more. This method allows continuous monitoring not only in the laboratory but also in the field. This method is suitable for deeply colored and suspended samples. Even samples containing iron and iodine fixed substances that interfere with the iodine titration method specified in JlS K 0400-32-10 (ISO 5813) can be measured using the electrochemical probe method. However, gases that permeate through the diaphragm, such as chlorine, sulfur dioxide, hydrogen sulfide, amines, ammonia, carbon dioxide, bromine, and iodine, can interfere, and their presence can affect the measured value. Others can cause problems, deteriorate the diaphragm, corrode the electrodes, and affect the current value. This includes solvents, oils, sulfides, carbonates, algae, etc. This method is also suitable for natural water, wastewater, and salt water. When measuring highly concentrated salt water such as seawater and estuary water, correction for salinity must be performed.
JIS K 0400-32-30:1999 history
1999JIS K 0400-32-30:1999 Water quality -- Determination of dissolved oxygen -- Electrochemical probe method