14
G
HYGRASGARD
®
AFTM- ⁄ KFTM - LQ - CO2 - Modbus
Rev. 2021 - V25
The maintenance-free, microprocessor-controlled on-wall or duct sensor with Modbus connection, with ⁄ without optional display,
is used to monitor all
measurands of relevance to the climate inside a room. These are the measurands air humidity, temperature, CO2
concentration as well as air quality (VOC).
By using a single device to monitor all four measurands, it is possible to effectively monitor and regulate the entire room climate. It measures CO2 in the
range of 0...5000 ppm, the air quality (0…100 % VOC), temperatures in the range of –35...+80 °C, as well as relative air humidity from 0...100 % r.H. A
digital, long-term stable sensor used as measuring element for relative air humidity and temperature guarantees exact measurement results. The Modbus
can be used to retrieve the following parameters: Temperature [°C], relative humidity [% r.H.], air quality (VOC) [%], carbon dioxide (CO2) [ppm] and atmos-
pheric pressure [hPa]. The CO2 content of the air is measured using an optical NDIR sensor (non-dispersive infra-red technology). The detection range of
the sensors is calibrated for standard applications such as monitoring residential rooms and conference rooms. Room ventilation on an as-needed basis,
improved well-being and customer benefit, increased comfort as well as reduced operating costs through energy conservation are just some of the benefits
of employing the AERASGARD
®
CO2 sensor. The explanations above demonstrate that there are applications for CO2 measurements, for VOC measure-
ments, but from our perspective, above all, for a combination of both measurands. The crucial factor in this respect is that both of these measurands are
not convertible into each other and derivations to or from one another cannot be made. An NDIR CO2
measuring instrument measures selectively and cannot
detect any VOC; a VOC mixed gas sensor cannot recognize CO2 molecules. One sensor for every 30 m² of space is recommended.
TECHNICAL DATA
Voltage supply:
24 V AC ⁄ DC (± 10 %)
Power consumption:
< 4.8 W ⁄ 24 V DC typical; < 6.8 VA ⁄ 24 V AC typical; peak current 200 mA
Data points:
Temperature [°C], relative humidity [% r.H.], air quality (VOC) [%], carbon dioxide (CO2) [ppm], atmospheric pressure [hPa]
HUMIDITY
Sensors:
digital humidity sensor with integrated temperature sensor,
low hysteresis, high long-term stability
Sensor protection:
plastic
sinter filter, Ø 16 mm, L = 35 mm, exchangeable (optional
metal
sinter filter, Ø 16 mm, L = 32 mm)
Measuring range, humidity:
0...100 % r. H.
Operating range, humidity:
0...95 % r. H. (without dew formation)
Deviation of humidity:
typically
± 2.0 %
(20...80 % r. H.) at +25 °C, otherwise ± 3.0 %
TEMPERATURE
Measuring range, temperature: –35...+80 °C
Operating range, temperature:
–10...+60 °C
Deviation, temperature:
typically ± 0.2 K at 25 °C
AIR QUALITY (VOC)
Sensor, VOC:
VOC sensor (metal oxide)
with automatic calibration
(VOC = volatile organic compounds)
Measuring range, VOC:
0...100 % air quality; referred to calibrating gas;
multi-range switching
VOC sensitivities (low/medium/high)
Measuring accuracy, VOC:
± 20 % of final value (referred to calibrating gas)
Service life:
> 60 months (under normal load conditions)
CARBON DIOXIDE (CO2)
Sensor, CO2:
optical NDIR sensor (non-dispersive infra-red technology) including atmospheric pressure compensation (up to 1100 mbar)
with manual calibration (via zero button)
with automatic calibration (can be deactivated via Modbus)
Measuring range, CO2:
0...5000 ppm
Measuring accuracy, CO2:
typically ± 30 ppm ± 3 % of measured value
Temperature dependence, CO2: ± 5 ppm ⁄ °C or ± 0.5 % of measured value ⁄ °C (whichever is higher)
Pressure dependence:
± 0.13 % ⁄ mm Hg
Long-term stability:
< 2 % in 15 years
Gas exchange:
by diffusion
Bus protocol:
Modbus (RTU mode), address range 0...
247
selectable
Signal filtering:
4 s / 32 s
Ambient temperature:
–10...+60 °C
Response time:
< 2 minutes, minimal flow velocity 0.3 m/s (air)
Electrical connection:
0.2 - 1.5 mm
2
, ia push-in terminal
Housing:
plastic, UV-resistant, material polyamide, 30 % glass-globe reinforced, with quick-locking screws (slotted ⁄
Phillips head combination), colour traffic white (similar to RAL 9016),,housing cover for display is transparent!
Housing dimensions:
126 x 90 x 50 mm (Tyr 2)
Cable connection:
cable gland
, plastic (M 16 x 1.5; with strain relief, exchangeable, inner diameter 10.4 mm)
or
M12 connector
according to DIN EN 61076-2-101 (optional on request)
Protective tube:
KCO2
/
KLQ - CO2
/
KFTM - CO2
/
KFTM - LQ - CO2 - Modbus (patent no. DE 10 2014 010 719.1):
PLEUROFORM
TM
,
material polyamide (PA6), with torsion protection, Ø 20 mm, v
max
= 30 m/s (air)
without filter: NL = 202.5 mm / with plastic filter: NL = 235 mm (optional with metal filter: NL = 227 mm)
AFTM - CO2
/
AFTM - LQ - CO2 - Modbus:
stainless steel V2A
(1.4301)
,
Ø 16 mm,
with plastic sinter filter: NL = 55 mm (optional with metal sinter filter: NL = 47 mm)
Process connection:
KFTM - LQ - CO2 - Modbus:
via mounting flange made of plastic (included in scope of delivery)
AFTM - LQ - CO2 - Modbus:
by screws
Protection class:
III (according to EN 60 730)
Protection type:
KCO2
/
KLQ - CO2
/
KFTM - CO2
/
KFTM - LQ - CO2 - Modbus: IP 65
(according to EN 60 529)
housing in the built-in state (permeable PLEUROFORM: IP 30)
AFTM - CO2
/
AFTM - LQ - CO2 - Modbus: IP 65
(according to EN 60 529)
Standards:
CE conformity, electromagnetic compatibility according to EN 61 326, EMC Directive 2014 ⁄ 30 ⁄ EU
Optional:
Display with illumination,
three-line,
cutout approx. 70 x 40 mm (W x H), for displaying actual humidity,
actual temperature, air quality and the actual CO2 content (cyclic) or a selectable parameter (static)
or an individually programmable display value (The Modbus interface allows the display to be individually
configured in the 7-segment area and in the dot-matrix area.)
