Oxygen transmitters

Oxygen transmitters are crucial devices in various industries for accurately measuring oxygen concentration. They play a significant role in ensuring process safety, quality control, and environmental monitoring.

Working Principles

Electrochemical Sensors: These sensors operate based on the electrochemical reaction of oxygen at the electrodes. When oxygen comes into contact with the electrolyte in the sensor, a current is generated between the working electrode and the counter electrode. This current is directly proportional to the oxygen concentration.

Zirconia Sensors: Zirconia sensors utilize the oxygen - conducting property of zirconia at high temperatures. When there is a difference in oxygen concentration on both sides of the zirconia, oxygen ions will migrate, creating an electromotive force. This electromotive force has a linear relationship with the logarithm of the oxygen concentration difference.The zirconia sensor in it provides a fast response time and a long service life with almost no drift.

Applications

Industrial Processes: In the gas generation (oxygen/nitrogen) industry, oxygen transmitters are used to monitor and control the oxygen concentration in the production process. For instance, in nitrogen generation, the minimum output range of 0 to 10 ppm of some transmitter is ideal for ensuring the purity of nitrogen. In the additive manufacturing process, accurate oxygen concentration monitoring is necessary to prevent oxidation of the materials being processed.

Environmental Monitoring: In environmental applications such as wastewater treatment, surface water monitoring, and process water treatment and monitoring. It helps in maintaining the proper oxygen levels for efficient treatment and ecological balance.

Medical and Food Industries: In the medical field, oxygen transmitters are used to measure the oxygen purity in medical - grade oxygen, ensuring patient safety. In the food industry, they are used to monitor the oxygen concentration in food packaging. By controlling the oxygen level, the shelf - life of food can be extended. For example, monitoring the oxygen concentration in packaging helps prevent spoilage and maintain food quality.

Hazardous Area Monitoring: Oxygen transmitters with intrinsically safe designs, like those from Applied Sensing Technologies, are used in Class I Div I Group IIC hazardous areas. They are crucial for continuous monitoring in processes such as glove boxes, where accurate oxygen concentration measurement is essential to prevent potential explosions or ensure the proper operation of the enclosed environment.

Features of Oxygen Transmitters

Multiple Output Options: Many oxygen transmitters support various output signals, such as 4 - 20mA analog signals and digital signals like RS485 Modbus protocol. This allows for easy integration with different control systems like PLCs and DCSs, enabling remote monitoring and data recording. For example, the ExTox 211208 Sens O2 - 25 - EC supports both analog (4 - 20mA) and digital (RS485) outputs for seamless connection to existing industrial control systems.

Compact and Robust Design: Devices like the SenzTx are lightweight (less than 0.3 kgs) and robust, making them suitable for different installation scenarios. Their compact size also allows for easy integration into existing systems.

Long - term Stability and Low Maintenance: Some sensors, such as the zirconia sensors in certain transmitters, have a long service life with minimal drift. Electrochemical sensors, after strict aging tests and calibration, also offer good long - term stability, reducing the frequency of maintenance and calibration, thus cutting down costs. For example, the unique two - chamber oxygen cell design of the XMO2 smart oxygen analysis transmitter makes it immune to pollutants and changes in flow rate, requiring zero - point and full - scale calibration only twice a year.

In conclusion, oxygen transmitters are versatile and essential devices across multiple industries, and their continuous development is enhancing their performance and expanding their application scope.