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A Particle is a very small solid element. They remain in suspension in our environment. They are omnipresent in the air that surrounds us and can be found in various numbers depending on our location.

Particles mainly come from two different sources : natural or anthropogenic.  Here are some examples for each category :

  • Saharan winds generate natural particles.
  • Cars generate anthropogenic particles through their exhausts.

The original source of the particle will usually determine its chemical nature (size, composition,…)

Particles sources 

To this day the EU has set a threshold regarding the amount of particles in the air.

There are different reasons but mainly because it has been proven that a poor air quality can reduce life expectancy.

Many research from the World Health Organisation demonstrate that a poor air quality (especially due to fine particles pollution) generates several millions of premature death each year worldwide.

There are many different ways of measuring particles in the air, our NextPM uses optical measure (OPC technology). Optical measure is used to count the number of particles. Basically, a laser will enlighten a measuring cell and the particles will pass through the laser beam and be detected and counted.

NextPM: Outdoor environments, transportation, industry, smart cities …

NextOPC: Very low pollution environments, like cleanrooms, hospitals, pharmaceuticals applications, specific setting

NextPM LiteIndoor, smart buildings

More information

OEM Sensors

3 products answering 100% of the market needs

NextPM for Outdoor environments, transportation, industry, smart cities …

NextOPC for Very low pollution environments, like cleanrooms, hospitals, pharmaceuticals applications, specific setting

NextPM Lite for Indoor, smart buildings

PM stands for Particulate Matter, and the number attached corresponds to the diameter size of the particles in micrometers.

The units usually used for PM concentration are in µg per cubic meter.

For instance PM1 corresponds to the mass attributed to all particles below 1 µm of diameter size in a total volume of 1 cubic meter.

Size: particles from 0.3 to 10 µm 

Mass: from 0.1 to 1000 µg/m3

Detection Limit: < 1 µg/m3

Resolution: 0.1 µg/m3

Precision: linearity < 5%

The supply range is between 4.7 et 5.3 VDC to power NextPM & NextOPC.

The heater will switch on when internal RH is over 60% and PWM is used to control the heater to stabilize this RH to 60% max.

The heater will use 300 mA maximum current at the maximum heating power.


Protocol: UART/Modbus

Acquisition frequency: 1 second – 10 seconds – 1 minutes

Communication option: Running average 10 – 60 – 900 sec (respectively)

To communicate in RS485

Yes. It is possible to connect an Arduino.

Please check the following link for more information : GITHUB NextPM Arduino

Note : TERA Sensor is not responsible for any development from the GITHUB community and will not ensure any after sales services.


Our sensors can have a Lifespan of 10 000 hours (1.14 years for non stop use)

They can go up to 10 years depending on the settings


Grids: to avoid any parasites to get into the sensor 

USB plug & play cable: to start measuring PM in real time with your computer 

Software: showing real time PM level on your computer (for proof of concept use)

Distribution Network

You can find our Distribution network on our Order page to the following link :

You can contact us directly to :

OR fill in a request to the following link :

About TERA

Check out our company profile and discover GROUPE TERA, an air quality actor for more than 20 years.

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