Ozone sensor is a kind of ozone gas composition, concentration and other information into the information can be used by personnel, instruments, computers and other devices.
According to the different working principles, ozone sensors have the following types:
1,Ssemiconductor ozone sensor
This type of sensor is simple to manufacture and has the advantages of low cost, high sensitivity, fast response speed, long life, low sensitivity to humidity and simple circuit. The disadvantages are that it must work at high temperature, poor selectivity to odor or gas, scattered component parameters, unsatisfactory stability and high power requirements.
2, Solid electrolyte ozone sensor
It is a kind of chemical battery with ionic conductor as electrolyte, high conductivity, sensitivity and selectivity.
3, Polymer ozone sensor
It has the characteristics of easy operation, simple process, good selectivity at room temperature, low price, and easy to be combined with micro-structure sensors and surface wave devices.
4, Optical ozone sensor
It has the function of automatic correction and automatic operation. Its main advantages are high sensitivity and good reliability.
5, Electrochemical ozone sensor
The electrochemical oxidation process of ozone at the working electrode. The working electrode and the reference electrode of the electrolytic cell are kept constant at an appropriate potential through an electronic circuit. At which the electrochemical oxidation or reduction of ozone can take place. It is necessary to apply a specific voltage from the outside. And has the advantage of high sensitivity and good selectivity in gas detection.
Ozone sensor basic features:
The basic characteristics of gas sensors, such as sensitivity, selectivity and stability, are mainly determined by the choice of materials. Select appropriate materials and develop new materials to achieve better sensitive characteristics of gas sensors.
1. Sensitivity
Sensitivity refers to the ratio of the change in the output of the sensor to the change in the measured input. And mainly depends on the technology used in the sensor structure. Most gas sensors are designed based on biochemistry, electrochemistry, physics and optics. The first consideration is to choose a sensitive technology that is sensitive enough to detect the percentage of the valve limit (TLV-Thresh -old limit value) or leL-lower explosive limit of the target gas.
2, corrosion resistance
Corrosion resistance refers to the sensor’s ability to be exposed to a high volume fraction of the target gas. In the case of large gas leakage, the probe should be able to withstand 10~20 times the desired gas volume fraction. In return to normal operating conditions, sensor drift and zero correction should be as small as possible.
3. Selectivity
Selectivity is also known as cross sensitivity. This can be determined by measuring the sensor response produced by a particular concentration of interfering gases. This response is equivalent to the sensor response generated by a given concentration of ozone. This property is important in applications where multiple gases are tracked. Because cross sensitivity reduces repeatability and reliability of measurements, and the ideal sensor should have high sensitivity and high selectivity.
4. Stability
Stability refers to the stability of the basic response of the sensor during the whole working time, which depends on zero drift and interval drift. Zero drift refers to the change in sensor output response over the entire working time without ozone. Interval drift refers to the change in the output response of the sensor continuously exposed to ozone, which is shown as the decrease of the output signal of the sensor during the working time. Ideally, the zero drift of a sensor is generally within a certain range under continuous operating conditions.