Chemical oxygen demand (COD) digestion instrument and working method thereof

Abstract

The invention relates to the detection field, in particular to a chemical oxygen demand (COD) digestion instrument and a working method thereof. The COD digestion instrument comprises a control circuit board, a heating wire, a heating box, a heating disc and a control system used for controlling temperature of the heating disc. The heating wire is warped on the outer wall of the heating box and is connected with the control circuit board. The heating disc is arranged at the top of the hating box, and a plurality of heating holes are arranged on the heating disc. The control system is connected with the control circuit board and controls temperature of the heating disc by controlling opening and closing of the control circuit. The working method of the COD digestion instrument includes that when a sample is needed to be heated, the sample is placed in the heating box with the outer wall at the bottom and the outer portion of the lateral wall simultaneously heated to be heated. Compared with the prior art, the heating wire is wound on the outer wall of the heating box so that the whole heating box is located in the heated environment and temperatures at all positions of the heating box are even.

Description

technical field [0001] The invention relates to the detection field, in particular to a COD digestion instrument and a working method thereof. Background technique [0002] COD refers to chemical oxygen demand, which is to use chemical oxidants (such as potassium permanganate, etc.) to oxidize and decompose oxidizable substances (such as organic matter, nitrite, ferrous salt, sulfide, etc.) in water, and then Calculate the oxygen consumption. COD is an important index indicating the degree of water pollution. It is mainly used to measure the content of organic substances in water. The smaller the value, the lighter the degree of water pollution. [0003] At present, in the COD test, a COD digestion instrument is usually used to heat the reaction solution containing the sample and the oxidant to cause a redox reaction between the two to accelerate the digestion of the sample, so as to achieve complete oxidation of the organic substances in the sample, and then determine The...

AI Technical Summary

Problems solved by technology

The disadvantage of this heating method is that the temperature in the middle area at the bottom of the heating box is high, and the temperature in other areas is low, resulting in a difference in the heating temperature between the sample placed in the middle of the heating box and the sample placed on the edge, usually at least 3 As a result, in the same detection process, the degree of oxidation and digestion of different samples is inconsistent, which affects the consistency, accuracy and stability of the test results.

Images