What are the air purity sensors currently used for and how do they work?
Currently, several types of air purity sensors are used - among them there are electrochemical sensors, in which the measurement process consists of a chemical reaction of gases contained in the air with a measuring electrode placed in a liquid medium. In resistance and semiconductor sensors based on metal oxides, gases in the air react with the sensor surface, changing the resistance of its secondary measuring circuit. Another structure used in air quality monitoring is the photo-ionization sensor. Its operating principle is based on the ionization of volatile organic compounds, which in turn causes an electric current to flow in the secondary measuring circuit of the sensor. Air pollution can also be monitored by means of optical sensors that monitor how much gas or dust particles present in the air affect the splitting of light. Optical sensors can detect the presence of carbon monoxide (carbon monoxide) and carbon dioxide by measuring the amount of infrared light absorbed.
What factors affect the accuracy of measurements by sensors that monitor air quality parameters?
The parameters of the measurement signal coming from air purity sensors are influenced not only by the concentration of gases and clouds of dust in the air of interest to us but also by other environmental and hardware factors, such as the presence of substances undetectable by the sensors that may introduce measurement disturbances, temperature, humidity, pressure, as well as the signal drift depending on the electromagnetic compatibility parameters of the measurement system - e.g. in case of high air pollution, the measurement signal may be weakened by particles of other substances in the air, which may cause a measurement error. The accuracy of the measurement is also influenced by the design, construction, purpose of the sensor and the measuring system cooperating with it, including e.g. a microcontroller. Due to fluctuations in environmental conditions, sensor calibration alone may not be sufficient, and obtaining accurate and similar measurement results under similar environmental conditions, albeit in different measurement locations, may prove difficult to achieve. Despite this, gas, dust and air purity sensors successfully meet the hardware parameters of professional environmental monitoring stations. Air pollution sensors that are offered by our store are also an excellent offer for all enthusiasts of electronic metrology. If you like to design and build measurement systems, our range of measurement sensors will surely interest you. The air quality measurement sensors available in the Botland store are compatible with Arduino boards, and communication takes place via the I2C, UART interface, as well as the ADC converter.