Dissolved oxygen sensor is a key equipment used to measure the dissolved oxygen content in water bodies, widely used in environmental monitoring, aquaculture, sewage treatment, hydrological research and other fields. Its main characteristics can be summarized from multiple dimensions such as measurement principles, performance, and applicable scenarios, as follows:

1、 Diverse measurement principles, suitable for different scenarios

The core of dissolved oxygen sensors is to convert dissolved oxygen concentration into measurable electrical signals through specific principles, including:

·Electrochemical method (polarographic method)/Primary battery type：

oPolarographic formula: requires an external power supply to generate a current through the reduction reaction of oxygen on the electrode surface. The magnitude of the current is proportional to the concentration of dissolved oxygen, with high accuracy and requiring regular calibration.

oPrimary battery type: does not require an external power source, generates current through chemical reactions of electrode materials (such as silver and lead), has a simple structure and low cost, but has a short lifespan (limited by electrode material consumption).

·Optical method (fluorescence method)：
Based on the principle of fluorescence quenching, oxygen suppresses the luminescence intensity and lifetime of fluorescent substances, and the dissolved oxygen concentration is calculated by detecting changes in fluorescence. No need for frequent calibration, strong anti-interference ability (not affected by ions in water, hydrogen sulfide, etc.), suitable for long-term online monitoring.

2、 High precision and high sensitivity

·The measurement accuracy can usually reach ±0.1 mg/L(milligrams)/Rising) or±1% FS(Full range), some models can achieve±0.05 mg/LIt can capture small changes in dissolved oxygen in water bodies (such as concentration fluctuations caused by fish activities in aquaculture).

·High sensitivity, detectable0.01 mg/LDissolved oxygen meets the measurement requirements of low oxygen environments such as deep water bodies and anaerobic reactors.

3、 Good stability and reliability

·Optical sensors have better stability and smaller drift (usually less than monthly drift) due to the lack of electrode consumption1%）, with a lifespan of up to1-2Year; Electrochemical methods require regular replacement of electrolytes and membranes, but maintenance can ensure long-term stable operation.

·Equipped with anti-interference capabilities, such as waterproof and corrosion-resistant shells (suitable for harsh environments such as seawater and sewage), some models can resist biological adhesion (such as coating with anti fouling coatings), reducing the impact of algae and microorganisms on measurements.

4、 Quick response and real-time monitoring

·Short response time, usually within 30 Seconds to2 Stable readings can be achieved within minutes, which can reflect the dynamic changes of dissolved oxygen in water in real time (such as water stratification and diurnal fluctuations in algal photosynthesis).

·Supports online continuous monitoring and can be integrated with data collection systemsPLC(Programmable Logic Controller) linkage, realizing automatic alarm (such as triggering oxygenation equipment when dissolved oxygen is too low), widely used in automation control systems.

5、 Wide range and environmental adaptability

·The measurement range is usually0-20 mg/L(covering the dissolved oxygen range of natural water bodies), some models can be extended to0-50 mg/LTo meet the measurement requirements of high oxygen water bodies (such as oxygen enriched water and pure oxygen aeration systems).

·Adapt to different temperature and pressure conditions: Built in temperature sensor for temperature compensation (dissolved oxygen solubility changes with temperature), some models can withstand pressure (such as deep-sea exploration, with pressure resistance up to) 1000 Suitable for complex environments with a depth of meters.

6、 Convenient operation and maintainability

·Easy calibration: Supports air calibration (using known oxygen concentration in the air) or standard solution calibration, and some smart sensors can be automatically calibrated to reduce operational difficulty.

·Low maintenance cost: Optical sensors do not require frequent replacement of consumables; Although electrochemical methods require regular replacement of membranes and electrolytes, the operation process is simple and the maintenance cycle is usually1-3A month.

summary

The core characteristics of dissolved oxygen sensors areHigh precision, high stability, fast responseAnd through diverse measurement principles and structural designs, it adapts to different application scenarios (from laboratory testing to long-term field monitoring). When choosing, optical methods (low maintenance, high stability) or electrochemical methods (high cost-effectiveness, suitable for conventional scenarios) should be given priority based on factors such as measurement environment, accuracy requirements, and maintenance costs.