uRADMonitor model A3 uses the Bosch BME280 to measure air temperature, barometric pressure, humidity and humidity. A MOX VOC sensor measures volatile organic compounds
. A high quality laser scattering sensor is used to detect the Particulate Matter PM2.5
concentration in air. There are two electrochemical sensors, one for formaldehyde
sensor and another one for ozone and a nondispersive infrared sensor for CO2. A built in fan assures an active air flow stream across the sensing elements. There is also a noise level sensor.
|Sensor||Parameter||Minimum value||Maximum value|
|Bosch BME280||Temperature||-40 °C||+85 °C|
|Pressure||300 hPa||1100 hPa|
|Humidity||0% RH||100% RH|
|Winsen ZH03A||PM1.0||0 μg/m³|| 1000 μg/m³|
|PM2.5||0 μg/m³|| 1000 μg/m³|
|PM10||0 μg/m³|| 1000 μg/m³|
|Winsen ZE08-CH2O||Formaldehyde||0 ppm|| 5 ppm|
|Winsen ZE25-O3||Ozone||0 ppm|| 10 ppm|
|Winsen MH-Z19B||Carbon Dioxide||400 ppm|| 5000 ppm|
|Winsen MP503||VOC||10 ppm||1000 ppm *|
* VOC concentration interval is estimated for alcohol.
To see complete specs see the technical datasheet.
Many of the pollutants measured by Model A3 can have a negative impact on our health, ranging from simple allergies to various cancers. Therefore the data gathered by this device is valuable for our understanding on the quality of our
Picture: uRADMonitor fights pollution to improve our health
VOC or volatile organic compounds
are a class of substances that evaporate at room temperature. Being different
substances may be responsible for a broad category of disorders, including respiratory problems, allergic or weakening
immunity in children. Some VOC ‘s are responsible for the formation of smog, irritation of eyes, nose and throat,
headaches and concentration problems. In extreme circumstances, more severe complications can occur, such as
damage to liver, kidney and central nervous system or cancer 
Particulate matter PM2.5
refers to small particles with a diameter of up to 2.5 microns. These particles can penetrate
deep into the lungs , causing allergies, respiratory and cardiovascular diseases 
is a toxic colorless gas with a pungent smell, that results from the burning of carbon based materials. It
can be found in forest fires, in automobile exhaust and cigarette smoke. It is an allergenic and a known carcinogenic
compound that can cause serious health effects, depending on concentration and exposure. Even in tiny quantities just
above 0.1ppm it can irritate the eyes and nose, and can worsen asthma symptoms 
is a gas heavier than air. In small quantities of up to 5000ppm (0.5% ) can cause headaches, lethargy,
slowing of intellectual ability, irritability, sleep disturbance. In larger quantities can cause dizziness, loss of sight, hearing
or knowledge. The fresh air contains between 360ppm and 410 ppm of CO2 
can cause the muscles in the airways to constrict, trapping air in the alveoli. This leads to wheezing and
shortness of breath. Long-term exposure to ozone is linked to aggravation of asthma, and is likely to be one of many
causes of asthma development. Long-term exposures to higher concentrations of ozone may also be linked to
permanent lung damage, such as abnormal lung development in children. 
Noise Induced Hearing Loss (NIHL)
is the most common and often discussed health effect, but research has shown
that exposure to constant or high levels of noise can cause countless adverse health affects. 
 Volatile Organic Compounds’ Impact on Indoor Air Quality, US Environmental Protection Agency
 Health and Environmental Effects of Particulate Matter (PM), US Environmental Protection Agency
 ToxFAQs™ for Formaldehyde, Agency for Toxic Substances and Disease Registry
 Effects of low-level inhalation exposure to carbon dioxide in indoor environments
 Health Effects of Ozone Pollution, US Environmental Protection Agency
 Noise Pollution, US Environmental Protection Agency
The model A3 is designed as an automated, fixed, Air Quality monitoring station. The A3 is IOT and it comes in 4 variants, with the same sensors but offering different connectivity options: Ethernet, Wifi, GSM/GPRS and LoraWAN. It takes any voltage in the 6V - 28V interval and uses less than 1 Watt of power to run. A built in speaker can provide audible notifications, configurable via the dashboard
. This unit doesn't have a screen, it works as a monitor and the data can be viewed remotely on a computer
or on a mobile device
Picture: uRADMonitor A3 motherboard front and bottom view
|Voltage||External||6V - 28V|
|Connectivity||4 options||Ethernet, WiFi, GSM, LoRaWAN|
|Enclosure||Rugged aluminium||110x80x24 mm|
Your uRADMonitor unit can be mounted both indoors and outdoors, but not directly exposed to sun, to avoid overheating in warmer areas. A covered spot with some shadow if installed in the free air, is ideal. The unit has a rugged aluminium enclosure that is not rainproof due to the air vents. Make sure that nothing is blocking the air vents. The enclosure has wall-mounting brackets, making installation easy.
If you have a radio variant with an antenna, connect the antenna first. If it is the wired variant, connect it to the Internet Router using the Ethernet cable. Connect the uRADMonitor to the power source using a DC adapter with voltage between 6V and 28V or via the USB port with a 5V USB adapter.
The Ethernet variant
Make sure the device is connected to the Internet router using the Ethernet cable. Use a longer cable if needed. The Internet router must have DHCP enabled. When powered, the uRADMonitor gets an IP automatically, via DHCP, and will show up on the map automatically.
The WIFI variant
Use a smartphone or a computer with WLAN capabilities to connect to the local hotspot spawned by your A3 unit. The SSID is uRADMonitor-XX, where XX are the last two digits of the Device ID number. The key is the Device ID, in uppercase, as printed on the enclosure. Open 192.168.4.1 in your browser, and click the "WIFI" link to setup the connection to the Internet AP. Enter the SSID and key of your Internet Access Point. If the connection fails, you will see the status message, and three consecutive beeps will indicated the problem. Alternatively you can change the configuration using the USB data port. See the USB manual
The LORAWAN variant
Your device must be pre-provisioned with the LoraWAN Gateway and network server details. Alternativelly you can change the configuration using the USB data port. See the USB manual
The GSM variant
A data SIM card must be inserted in your A3 unit before it can connect over Internet.
Starting with hardware version HW106, the LoRaWAN, Wifi and GSM settings can be customized via the USB connection. Consult your product manual for complete details.