PMSA003 – Optical Particles Sensor

Since the corona virus I have become increasingly aware of my environment. I also started to delve deeper into my living environment and in particular the air quality. I Already wrote a blog about the NASA Clean Air Study, this blog explains how you can clean your indoor air with plants. But I don’t know how clean my air is, so I need a PMSA003 Optical Particulates Sensor.

Particulates

Also known as atmospheric aerosol particles, atmospheric particulate matter, particulate matter (PM), or suspended particulate matter (SPM) – are microscopic particles of solid or liquid matter suspended in the air. The term aerosol commonly refers to the particulate/air mixture, as opposed to the particulate matter alone. Sources of particulate matter can be natural or anthropogenic. They have impacts on climate and precipitation that adversely affect human health, in ways additional to direct inhalation.

Types of atmospheric particles include suspended particulate matter; thoracic and respirable particles; inhalable coarse particles, designated PM₁₀, which are coarse particles with a diameter of 10 micrometers (μm) or less; fine particles, designated PM_2.5, with a diameter of 2.5 μm or less; ultrafine particles; and so on.

The IARC and WHO designate airborne particulates a Group 1 carcinogen. Particulates are the most harmful form of air pollution due to their ability to penetrate deep into the lungs, blood streams and brain, causing health problems including heart attacks, respiratory disease, and premature death. In 2013, a study involving 312,944 people in nine European countries revealed that there was no safe level of particulates and that for every increase of 10 μg/m³ in PM₁₀, the lung cancer rate rose 22%. The smaller PM_2.5 were particularly deadly, with a 36% increase in lung cancer per 10 μg/m³ as it can penetrate deeper into the lungs. Worldwide exposure to PM_2.5 contributed to 4.1 million deaths from heart disease and stroke, lung cancer, chronic lung disease, and respiratory infections in 2016. Overall, ambient particulate matter ranks as the sixth leading risk factor for premature death globally.

AQI	Air Pollution Level	Health Implications	Cautionary Statement (for PM2.5)
0 – 50	Good	Air quality is considered satisfactory, and air pollution poses little or no risk	None
51 -100	Moderate	Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.	Active children and adults, and people with respiratory disease, such as asthma, should limit prolonged outdoor exertion.
101-150	Unhealthy for Sensitive Groups	Members of sensitive groups may experience health effects. The general public is not likely to be affected.	Active children and adults, and people with respiratory disease, such as asthma, should limit prolonged outdoor exertion.
151-200	Unhealthy	Everyone may begin to experience health effects; members of sensitive groups may experience more serious health effects	Active children and adults, and people with respiratory disease, such as asthma, should avoid prolonged outdoor exertion; everyone else, especially children, should limit prolonged outdoor exertion
201-300	Very Unhealthy	Health warnings of emergency conditions. The entire population is more likely to be affected.	Active children and adults, and people with respiratory disease, such as asthma, should avoid all outdoor exertion; everyone else, especially children, should limit outdoor exertion.
300+	Hazardous	Health alert: everyone may experience more serious health effects	Everyone should avoid all outdoor exertion

PMSA003 – Digital Laser Dust Sensor

The PMSA003 is a digital general-purpose particle concentration sensor that can be used to obtain the mass and quantity of suspended particulates in the air per unit volume and output as a digital interface form. The sensors can be embedded in a variety of concentrations of environment-related instruments suspended particulate matter in the air, to provide timely and accurate concentration data.

How it works?

This sensor uses the principle of laser scattering. Namely the scattering of laser irradiation in the air suspended particles, while collecting the scattered light at a specific angle, to obtain the scattering intensity versus with time curve. Microprocessor using based on the MIE theory of the algorithm, get the particle equivalent particle size and unit volume of particles of different particle size. The main CPU is a Cypress CY8C4245, which a combined ARM Cortex-M0 running at 48Mhz with dedicated ADC, used to sample the output from the diode

Technical details

Pinout

PIN 1 & 2	VCC	Power (5V)
PIN 3 & 4	GND	Ground
PIN 5	RESET	Module reset signal / TTL level @ 3.3V
PIN 7	SCL	I2C_SCL pin / TTL level @ 3.3V
PIN 9	SDA	I2C_SDA pin / TTL level @ 3.3V
PIN 10	SET	Setting pin / TTL level @ 3.3V
PIN 6 & 8	NC	Empty

Here you see the pinout for the PMSA003 module, starting with pin 1 in the lower left corner, above it pin number two and so on.

Yes! It works!