3
Product description
6062-en_V2.4_02/21
17
3.3
Functional description
The following descriptions refer to the fully equipped version of the devices.
The fully equipped version has to include all of the available packages.
Analysis of particles in
ambient air
Measuring devices in the series
AQ Guard
continuously analyze fine dust
particles from the ambient air and simultaneously calculate the immission
values PM
2,5
and PM
10
, which require monitoring. The values PM
1
, PM
4
,
PM
tot
, the particle number concentration C
n
and the particle size distribution
are calculated and recorded. The number of particles is determined by
means of optical light scattering.
Detection of CO
2
and
VOC
Sensors for CO
2
and volatile organic hydrocarbons (VOC) collect the data
required to determine the Air Quality Index (AQI).
Determination of basic
data of ambient air
Other sensors determine the basic data of the ambient air:
• Air temperature
• Air pressure
• Relative humidity
Scattered light analysis
The device works with the optical aerosol spectrometer that uses scattered
light analysis to determine the size of an individual particle. The single
particles move through an optically differentiated measurement volume that
is homogeneously illuminated with a polychromatic LED light source. Each
particle generates a scattered light pulse that is detected at an angle of 90°
degrees. The particle count is determined based on the number of scattered
light pulses. The level of the measured scattered light pulse is a measure of
the particle diameter.
Interfaces
The device has several data interfaces, enabling realtime access via
Ethernet, WiFi or mobile data. All of the measured values are calculated and
logged in the device. Evaluation with an external device is not required and
is not intended. This means that the user has complete control of the data
and can decide himself which information should be accessible.
Measured values can be displayed on the device’s screen or via a Web
interface. A built-in server transmits the data to external devices.
Power supply
There are three ways to supply power to the device:
• With an included power supply unit
• With a 12-volt direct current source
• With PoE (Power over Ethernet)
Unsupervised
continuous operation
The device is intended to be used continuously and without supervision. The
sampling head and the optical sensor system should be protected from
pollution to the greatest extent possible. The elements can be cleaned by
the user when necessary.