4
2. Function
The AirSafe PM uses a high end optical measurement system that is embedded in the sensor. The air flows
through the measuring device which counts the particles and defines their size. The raw measurement is
processed by a unique algorithm which enables continuous and accurate measurement for the different
sizes of particles as well as classification of A or E dust fractions (also known as inhalable and respirable
fractions).
2.1 Particles size / glossary
PM describe all dust particles smaller than the mentioned size.
Example:
PM1
include all dust particles smaller than 1
µ
m
PM2.5
include all dust particles smaller than 2.5
µ
m
PM4.5
include all dust particles smaller than 4.25
µ
m
PM10
include all dust particles smaller than 10
µ
m
TSP
refer to “Total suspended particles” with is equal
to all dust particles equal or smaller than 100
µ
m
European standard EN 481 also separate dust in 2 fractions:
•
E dust:
The respirable fraction – Particles equal or smaller than 100
µ
m
•
A dust:
The inhalable fraction – Particles equal or smaller than 4.25
µ
m
2.2 Compliance
This sensor comply with TRGS 900 and EN 481.