Desktop dissolved oxygen analyzer is an instrument widely used in water quality monitoring, environmental protection, and various industrial processes to measure the concentration of dissolved oxygen in water bodies. Dissolved oxygen is one of the important water quality indicators in water bodies, especially playing an important role in aquaculture, sewage treatment, drinking water monitoring and other fields. With the increasingly strict requirements for water quality, precision improvement and calibration methods have become particularly crucial. This article will explore methods for improving its accuracy and calibration.

1、 Precision improvement

1. The improvement of sensor technology:Desktop dissolved oxygen analyzerThe accuracy mainly depends on its dissolved oxygen sensor. Traditional dissolved oxygen sensors are mostly polarographic sensors that measure oxygen concentration through changes in current; In recent years, with the development of optical sensing technology, optical dissolved oxygen sensors have gradually been widely used. Optical sensors calculate dissolved oxygen concentration by measuring the decay time of fluorescence signals, which has high accuracy and is less affected by external factors such as temperature, salinity, and pressure. Improving the quality of sensors and selecting high-precision sensors can significantly enhance measurement accuracy.

2. Intelligent control system: With the application of intelligent technology, microprocessors and advanced software algorithms are commonly equipped. These systems can automatically compensate for external environmental factors such as temperature and air pressure, thereby improving the stability and accuracy of measurements. For example, dissolved oxygen concentration has a strong correlation with water temperature and air pressure. By using a built-in temperature sensor and combining it with a temperature compensation algorithm, errors caused by temperature fluctuations can be greatly reduced.

3. Data processing and calibration techniques: Its accuracy can also be improved by optimizing data processing and calibration techniques. Equipped with real-time data correction and automatic adjustment functions. For example, by utilizing historical data and multi-point calibration methods, automatic corrections can be made during the measurement process, thereby improving measurement accuracy. In addition, it is equipped with automatic recognition and alarm functions, which can detect abnormal values and remind users to avoid errors caused by human factors.

4. Sensor maintenance and cleaning: Sensors may be contaminated during long-term use, leading to measurement errors. Regularly cleaning sensors to ensure they are in optimal working condition is an important means of improving accuracy. In addition, regularly replacing sensors or repairing aging sensors can maintain the long-term stability and accuracy of the instrument.

2、 Calibration method

Regular calibration is crucial to ensure the accuracy of the desktop dissolved oxygen analyzer. There are two common calibration methods: zero point calibration and standard dissolved oxygen solution calibration.

1. Zero point calibration: Zero point calibration is the fundamental step of calibration. When performing zero calibration, it is usually placed in an environment where the dissolved oxygen is known to be zero (such as removing oxygen by chemical means or nitrogen inflation), and then the zero setting is adjusted. The purpose of zero point calibration is to eliminate sensor bias and ensure accurate instrument readings when the dissolved oxygen concentration is zero.

2. Calibration of standard dissolved oxygen solution: Standard dissolved oxygen solution is another common method of calibration. The commonly used standard dissolved oxygen solution is usually calibrated in a standard solution with known dissolved oxygen concentration. The concentration of a standard solution is usually calculated based on factors such as water temperature and air pressure, and can be prepared using standard samples.

3. Air saturation calibration method: The air saturation method is another common calibration method. In the air saturation method, it is placed in air at room temperature and pressure, and calibrated using the saturation concentration of dissolved oxygen in the air. This method is simple and fast, suitable for most water quality monitoring and laboratory applications. The concentration of dissolved oxygen in the air can be adjusted by instruments to make the reading consistent with the actual concentration.

The accuracy improvement of desktop dissolved oxygen meters relies on advanced sensor technology, intelligent control systems, and optimized data processing methods. Regular calibration, especially zero point calibration, standard dissolved oxygen solution calibration, and air saturation method calibration, is the key to ensuring instrument accuracy. By continuously optimizing equipment performance and scientific calibration methods, more accurate and reliable dissolved oxygen concentration measurements can be provided, providing important support for various water quality monitoring and industrial applications.