14
G
HYGRASGARD
®
AFTM- ⁄ KFTM - LQ - CO
2
- Modbus
Rev. 2019 - V23
Patented quality product (patent no. DE 10 2014 010 719.1)
The maintenance-free, microprocessor-controlled
AERASGARD
®
AFTM - LQ
- CO
2
- Modbus
and
KCO
2
⁄ KLQ - CO
2
⁄ KFTM - CO
2
- Modbus
with
Modbus connection, with ⁄ without optional display,
is designed for duct installation and is used to monitor all measurands of relevance to the climate
inside a room. These are the measurands air humidity, temperature, CO
2
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 CO
2
in the range of 0...5000 ppm, VOC at
one of three selectable sensitivity levels LOW / MEDIUM / HIGH, 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 (CO
2
)
[ppm] and atmospheric pressure [hPa].
The CO
2
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
®
CO
2
sensor.
The explanations above demonstrate that there are applications for CO
2
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 CO
2
measuring instrument measures selectively and cannot detect any VOC; a VOC mixed
gas sensor cannot recognize CO
2
molecules.
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 (CO
2
) [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 sensitivity low, medium, high
Measuring accuracy, VOC:
± 20 % of final value (referred to calibrating gas)
Service life:
> 60 months (under normal load conditions)
CARBON DIOXIDE (CO
2
)
Sensor, CO
2
:
optical NDIR sensor (non-dispersive infra-red technology) including atmospheric pressure compensation (up to 1100 mbar)
with automatic and manual calibration
Measuring range, CO
2
:
0...5000 ppm
Measuring accuracy, CO
2
:
typically ± 30 ppm ± 3 % of measured value
Temperature dependence, CO
2
: ± 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-stabilised, 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 gland:
2x M 16 x 1.5; including strain relief, exchangeable
Protective tube:
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)
Process connection:
via mounting flange made of plastic (included in scope of delivery)
Protection class:
III (according to EN 60 730)
Protection type:
IP 65 (according to EN 60 529) housing only! (PLEUROFORM IP 30)
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 CO
2
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.)
