Under the order. The operation of the device can be viewed in our office.
As a result of atmospheric pollution by products of combustion of fossil fuels, about 20 billion tons of carbon dioxide enter the atmosphere every year.
Atmospheric pollution, according to WHO experts, leads to the death of about 3 million people annually. Today air pollution is environment, and indoors - this is the biggest environmental health risk.
However, for each person, specific conditions in the place of his residence are important.
The quality of indoor air is primarily determined by the environmental friendliness of building materials and furniture materials, the performance of ventilation and air conditioning systems, the quality of cleaning and ventilation of the premises.
Every modern man is facing a problem feeling unwell in rooms with optimal climatic conditions, equipped with air conditioning systems. The explanation for this is quite simple. Closed spaces with poor ventilation accumulate carbon dioxide and fine aerosol microscopic particles. Air conditioning systems do not provide air purification from microparticles; moreover, by creating air flows, microparticles are maintained in the atmosphere of the room in a suspended state.
The presence of carbon dioxide in the inhaled air, even in small quantities, is harmful and dangerous to health.
Therefore, in residential areas, especially where there are children, monitoring of air quality is necessary.
Microscopic particles and aerosols do not lead to a rapid onset of poor health, but they have a cumulative effect, and depending on their size, their effect on the body manifests itself in different ways. Due to their small size, these particles have the property of hanging in air currents, therefore they are officially called suspended particles (PM - particulate matter).
Unlike larger particles, PM2.5 easily penetrates biological barriers, settles in the lungs and therefore poses the greatest threat to the body.
These global changes and the disappointing results of research make us think about how to protect people's health in these difficult conditions (peat fires, city dust and smog), because a person cannot always see and understand that the air is polluted and very dangerous for life. HEPA filters are used to purify the air, and AirCheck will help determine the quality of their work.
Devices whose main purpose is to measure the dose rate of radiation (alpha, beta and gamma, taking into account X-ray) and thereby check for the radioactivity of suspicious objects.
Dosimetric devices are used to determine the levels of radiation in the area, the degree of contamination of clothing, skin people, food, water, fodder, transport and other various objects and objects, as well as to measure the doses of radioactive exposure of people when they are at objects and areas contaminated with radioactive substances.
They are used for chemical analysis of air, which provides information on the qualitative and quantitative composition of pollutants and allows predicting the degree of pollution. The main indoor pollutants include interior items, furniture, floor and ceiling coverings, construction and Decoration Materials. Chemical analysis of air reveals indicators such as dust, sulfur dioxide, nitrogen dioxide, carbon monoxide, phenol, ammonia, hydrogen chloride, formaldehyde, benzene, toluene, etc.
Instruments for measuring the hydrogen index (pH index). Investigate the activity of hydrogen ions in solutions, water, food products and raw materials, environmental objects and production systems, including in aggressive environments.
Serve to assess the quality of drinking water. Show the amount of inorganic impurities suspended in water, mainly salts of various metals. In everyday life, they are used to determine the quality of tap water, bottled water, as well as to control the effectiveness of water treatment filters.
Portable instruments designed to measure the exact sound level. Noise is called an environmental pollutant. It is also harmful tobacco smoke like exhaust gases, like radiation activity. Noise can have a total of four types of source. Therefore, it is customary to divide it into: mechanical, hydromechanical, aerodynamic and electromagnetic. Modern appliances are able to determine the noise level of any mechanisms: land, water and even lines electrical transmission. The device will allow you to objectively measure the sound volume level.
Portable devices designed to measure the exact level of illumination produced by various light sources. The scope of luxmeters is wide, which is explained, first of all, by their high spectral sensitivity, which approaches the sensitivity of the human eye. Please note that some sources lighting fixtures, halogen, fluorescent and even LED bulbs, after some time of operation, they lose a significant amount of luminous flux, the overall illumination in the room may deteriorate. This will not only reduce the visual acuity of a person, but will also affect his fatigue. Illumination should be constantly monitored.
Devices designed for express determination of the amount of nitrates in vegetables, fruits, meat and other food products. Not so long ago, to conduct such studies, an entire laboratory was required, now it can be done using one compact device.
Portable nitrate meters have gained wide popularity due to their compactness, low cost and ease of use. Nitrates are present in many fertilizers that are actively used in agriculture to increase crop yields. For this reason, nitrates in vegetables and fruits are often found in significant concentrations. Getting into the human body with food, nitrates in large quantities can cause nitrate poisoning, various disorders and chronic diseases.
The nitrate indicator will help you recognize dangerous products in time and protect yourself from nitrate poisoning.
In any more or less large industrial city and its environs, the air is polluted with a large amount of suspended particles. And these are, for the most part, third-party substances that the industry works with, plus other man-made components, decay products formed during combustion, and so on.
In general, all this is very unhealthy, and in some cities people even have to wear protective masks, in the case of a particularly active phase of production and a certain configuration of the wind rose.
This solution is a small module for mobile phone, which evaluates air quality using the device's camera and flash. Of course, using the module on a phone without a camera and without a flash will not work.
The module itself is attached to reverse side smartphone using a magnet, while the holes of the module should be located above the flash and camera of the smartphone.
Everything works quite simply. A person presses the “take a photo” button (while setting the flash mode), the flash fires, and the light from it enters the camera sensor via an optical fiber.
The module also has a passive air intake through which the light from the flash passes before reaching the camera lens. The more suspended particles in the selected air sample, the more light is scattered.
For their module (its body, by the way, was printed on a 3D printer), the scientists also developed a corresponding application that analyzes the images received by the camera, calculating the number of particles in the air from the brightness of the pixels in the resulting image. According to experts, the brightness of the pixels in the photo allows you to quite accurately calculate air pollution, for which a special algorithm was developed.
After testing their device, the scientists compared their own results of research on the state of the atmosphere with the results of studies of regular stations for determining air quality. The results agreed pretty well.
Of course, the device has its limitations. In particular, it can detect atmospheric pollution at a concentration of suspended particles up to about 1 milligram per cubic meter. In addition, particles smaller than 10 microns (and the fine dust fraction is the most dangerous, by the way) are also not yet detected by the device.
Now scientists are improving the characteristics of the device, so that it can take into account the fine fraction of dust.
According to the developers, their device can be useful to all people, users of mobile devices, who are concerned about the quality of the atmosphere in their city. With the help of such a device and an application to it, it would be possible to quickly map the air pollution of a city/region, after which the results would be provided to the relevant services.
The scientists' article is available at
Such a device can help monitor air quality, as well as warn the owner of a gas leak or the presence of combustible gases. For added functionality, the detector includes a humidity and temperature sensor. This mini-station will be able to determine all major atmospheric pollutants (carbon monoxide, nitrogen oxide, sulfur dioxide, ozone and particulate matter), except for sulfur dioxide.
Due to the fact that the sensors used have different price and their parameters differ from one another; their calibration took place at gas concentrations known to the author.
Materials:
- Arduino Uno
- Power supply 5V
- LCD shield RGB 16x2 LCD shield
- Gas sensor MiSC-2614 (Ozone)
- Gas sensor MQ-9
- Keyes DHT11 humidity and temperature sensor
- Particulate matter sensor Shinyei PPD42
- Gas sensor MQ-2
- Gas sensor MiCS-2714 (NO2)
- Access to a 3D printer (for the case, you can use the available plastic or wooden box)
- Bread board
- Fan 5V
- Conductors caliber 24 (0.511 mm) 10 - 15 pcs
Wiring diagram:
This diagram shows the general scheme of the device to get an idea of what this detector is like. The author asks to pay attention to the fact that most ports with sensors can be changed, but then you will need to change the program code.
Step one. Particulate sensor.
Two Shinyei PPD42 sensors are used to collect particulate data.
Each of them has two outputs: the left one is yellow for small solids, and the second one for large particles. The outputs will be connected to the Ardiuno with a 5V supply voltage, as shown in the general diagram.
Each of the sensors uses an LED and a photodiode to measure the concentration of particles in the air.
Step two. Gas sensor board.
The circuit board of the gas and temperature sensors with humidity is shown below. Author printed circuit board I made it myself and recommends that those who will deal with this project also do it, and notes that the board may differ physically from the one indicated on the diagram.
Step three. NO2 and ozone sensors.
The homemade uses MiCS-2614 and MiCS-2714 surface mount sensors, they detect ozone and ozone dioxide in the air.
Each sensor uses an internal resistor in its sensor element. The diagram shows the location of the measuring resistor between terminals K and G. To determine them correct location an ohmmeter was used. The resistance of the resistor is in the range of kOhm. The sensors also have a heating element between terminals H and A, which maintains the temperature of the sensor element. The heating element has a resistance of 50-60 kOhm.
Step four. Gas sensors.
The author uses gas sensors MQ-2 and MQ-9, which measure toxic gases. The sensors use a gas sensing resistor to detect toxic gases, and use their heating element to set and maintain the desired sensor temperature.
Sensors are installed according to the scheme breadboard. The MQ-2 sensor is connected with the pin labeled A to the 5V supply, pin G to ground, pin S to ground through a 47 kΩ resistor. The MQ-9 sensor is connected a little differently: pin A to the transistor, B to the 5V supply, pin G to ground, and pin S to ground through a 10 kΩ resistor.
Step five. Humidity and temperature sensor.
This sensor is a must as humidity and temperature control is a very important part in determining the concentration of gases. Elevated values of humidity and temperature will greatly affect the accuracy of measurements. Both of these parameters can be monitored using a single sensor. Its connection is as follows: the left pin is connected to power, the middle pin is a signal output, and the right pin is connected to ground. The signal from this sensor will be sent to the Arduino digital port.
Step six. Fan and power supply.
If you look at the circuit of the entire project, you will notice that only one 5V input voltage is used. This homemade product uses a regular network adapter. For correct operation device, and a 5V case fan is used to prevent overheating.
Step seven. Frame.
The case can be made from improvised materials such as wood, metal, plastic. The author used a 3D printer, a file for printing is attached at the bottom of the article.
