Chemical oxygen demand (COD) is one of the important indicators for evaluating the degree of water pollution and is widely used in environmental monitoring, sewage treatment and other fields. As a commonly used measurement tool, the accuracy of COD analyzer is of great significance for water quality assessment. However, in practical applications, the measured value of the COD analyzer is affected by many factors. This article will explore these factors from multiple aspects and propose corresponding improvement measures to improve the accuracy and reliability of COD analyzers.

Influence of reagents and reference materials

The measured value of the COD analyzer is affected by the reagents and reference materials. Factors such as the purity, stability and storage conditions of the reagent may affect the measurement results. Therefore, when using a COD analyzer, high-quality reagents should be selected, and the reagents should be prepared and stored in strict accordance with standard operating procedures. In addition, the accuracy and stability of the standard material also have an important impact on the measured value of the COD analyzer. Standard materials should be calibrated regularly to ensure their accuracy and stability.

Influence of water sample properties

The properties of water samples have a significant impact on the measured values of the online COD analyzer. For example, factors such as pH value, temperature, turbidity, and color of water samples may affect the measurement results. To reduce these effects, water samples should be appropriately pretreated before sampling, such as adjusting pH, reducing turbidity and color, etc. In addition, the type and concentration of organic matter in the water sample will also affect the measured value of the online COD analyzer. Therefore, in practical applications, appropriate COD detection methods should be selected based on the characteristics of water samples.

Influence of instrument performance

The impact of the performance of the online COD analyzer on the measured values cannot be ignored. The accuracy, stability, sensitivity and other factors of the instrument will all affect the measurement results. Therefore, when using a COD analyzer, the instrument should be calibrated and maintained regularly to ensure that its performance is stable and reliable. In addition, the operation mode of the instrument will also affect the measured value. Operators should be familiar with the working principle and operating procedures of the instrument to avoid deviations in measurement results due to improper operation.

Influence of environmental factors

Environmental factors such as temperature, humidity, air pressure, etc. will also affect the measured value of the online COD analyzer. Changes in these environmental factors may cause instability in instrument performance, thereby affecting the accuracy of measurement results. Therefore, when using a COD analyzer, attention should be paid to maintaining a stable laboratory environment, such as controlling temperature, humidity and other conditions, to reduce the impact of environmental factors on the measurement results.

Improvement measures

In order to improve the accuracy and reliability of the online COD analyzer, the following improvement measures can be taken:

1. Optimize the selection and storage conditions of reagents and reference materials to ensure the purity and stability of reagents and the accuracy of reference materials;

2. Improve the pretreatment method of water samples to reduce the impact of water sample properties on measurement results;

3. Calibrate and maintain the online COD analyzer regularly to ensure stable and reliable instrument performance;

4. Strengthen laboratory environment control and maintain the stability of the laboratory environment;

5. Improve the skill level of operators and reduce deviations in measurement results caused by improper operation.

To sum up, the measured value of the online COD analyzer is affected by many factors. To improve the accuracy and reliability of measurement results, it is necessary to comprehensively consider various factors such as reagents and reference materials, water sample properties, instrument performance, and environmental factors, and take corresponding improvement measures. Only in this way can the role of COD analyzers be better utilized in the fields of water quality monitoring and sewage treatment, and contribute to environmental protection and sustainable development.