Datasheet

8
ENS160 Datasheet v0.95 preliminary / December 2020
5 Air Quality Signal Characteristics
To satisfy a wide range of individual application requirements, the ENS160 offers a series of
(indoor) air quality output signals that are derived from various national and international,
as well as de-facto standards. Table 4 provides a summary of such signals, with further
description in the following sections.
Table 4: Air Quality Signal Output Characteristics
Parameter
Range
Resolution
Unit
Comment
TVOC
0  65 000
1
ppb
For requirements outside these
specified ranges please contact us
eCO
2
400  65 000
1
ppm CO
2 -
equiv.
AQI-UBA
1
1 to 5
1
-
5.1 TVOC – Total Volatile Organic Compounds
More than 5000 VOCs exist, and they are two to five times more likely to be found indoors
than outdoors. Indoor VOCs are various types of hydrocarbons from mainly two sources: bio-
effluents, i.e. odors from human respiration, transpiration and metabolism, and building
material including furniture and household supplies. VOCs are known to cause eye irritation,
headache, drowsiness or even dizziness  all summarized under the term Sick Building
Syndrome (SBS). Besides industrial applications, comfort aspects (e.g. temperature), or
building protection (humidity), VOCs are the one and only root cause for ventilation.
To group and classify VOCs, regional guidelines and industry-preferences define a series of
compounds and mixtures as reference. E.g. ethanol, toluene, acetone, combinations of the
various groups of VOCs (e.g. ISO16000-29), and others.
The ENS160 supplies calibration to ethanol for best, most balanced TVOC-results.
Refer to DATA_TVOC (Address 0x22)on how to obtain TVOC-values from
the ENS160.
5.2 eCO
2
– Equivalent CO
2
Due to the proportionality between VOCs and -CO
2
generated by humans, CO
2
-values
historically served as an air quality indicator, reflecting the total amount of VOCs (=TVOCs)
produced by human respiration and transpiration. This law (first revealed by Max von
Pettenkofer
2
in the 19
th
century) and the unavailability of suitable VOC measurement
technology made CO
2
the surrogate of inhabitant-generated air-pollution in confined living
spaces of the past and the present, i.e. -
controlled ventilation  as adopted by most HVAC industry standards.
1
Classified TVOC output signal according to the indoor air quality levels by the German Federal Environmental Agency (UBA,
2007)
2
Max von Pettenkofer (*1818  .