Hydrogen sensor working principle
What is an o2 sensor?
O2 sensor is an instrument that can measure oxygen concentration, also known as oxygen sensor. Its principle is to use a chemical reaction to react oxygen with the material on the electrode surface, thereby generating a current signal to measure the oxygen concentration.
Oxygen sensor types
There are many types of oxygen sensors, the common ones include oxygen ion sensors, electrochemical oxygen sensors, optical sensors, etc. Different oxygen sensors have different advantages and disadvantages, so when selecting an oxygen sensor, you need to choose according to the specific application scenario. This article mainly introduces electrochemical oxygen sensors.
Oxygen sensor applications
Oxygen sensors are widely used in various fields such as the automotive industry, industrial process control, medical equipment, etc.
1. In the automotive industry, the main function of the oxygen sensor is to monitor the oxygen content emitted by the engine and convert it into an electrical signal. This electrical signal is sent to the engine control unit (ECU) so that the ECU can adjust the fuel and air mixture based on this data. If the oxygen sensor detects that the oxygen content of the engine exhaust is too high or too low, the ECU will adjust the fuel and air mixture ratio to ensure that the engine can operate normally.
2.In industrial process control, oxygen sensors can be used to monitor the oxygen concentration during the combustion process to control the temperature and combustion efficiency of industrial furnaces.
3.In medical equipment, it can be used in oxygen generator control systems, medical ventilators, anesthesia equipment and other equipment to detect the oxygen content in respiratory gas mixtures.
How oxygen sensors work
Electrochemical oxygen sensors usually consist of electrode materials and electrolytes. Among them, electrode materials include platinum, palladium, nickel, chromium, etc. These electrode materials serve as electrodes in electrochemical reactions to reduce oxygen ions into oxygen molecules. The electrolyte is usually a solution containing oxygen, hydroxyl ions, and hydrogen ions. Oxygen and hydroxide ions generate water molecules and oxygen molecules during the reduction and oxidation processes of the electrode, while hydrogen ions are reduced to hydrogen gas molecules.
When oxygen in the air enters the sensor through the sensor’s air inlet, it reacts with the electrode material and electrolyte to generate an electric current. According to the working principle of the electrochemical oxygen sensor, the oxygen sensor generates a reaction current, which can be used to detect changes in oxygen concentration produced during breathing. Specifically, when the oxygen concentration decreases during breathing, the electrode material will undergo a reduction reaction, producing more oxygen molecules, resulting in an increase in reaction current; conversely, when the oxygen concentration increases during breathing, the electrode material will undergo an oxidation reaction. , producing fewer oxygen molecules, resulting in a reduction in reaction current.