14
G
HYGRASGARD
®
AFTM- ⁄ KFTM - LQ - CO
2
- Modbus
Rev. 2018 - V22 GB
The maintenance-free microprocessor-controlled on-wall or duct sensor with Modbus connection with/without optional display
is an all-in-one device used
for detecting all relevant measured values, such as humidity, temperature, CO
2
concentration and air quality (VOC), thus enabling effective monitoring
and control of the entire room climate. It measures CO
2
in the range from 0...5000 ppm, VOC in one of three selectable sensitivity levels LOW / MEDIUM
/ HIGH, temperatures in the range from –35...+80 °C as well as relative air humidity of 0...100 % r.H. Relative humidity (% r.H.) is the quotient of water
vapour partial pressure divided by the saturation vapour pressure at the respective gas temperature. A digital, long-term stable sensor as a measuring
element for relative humidity and temperature guarantees exact measurement results. 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
. The above explanations demonstrate that
there are applications for CO
2
measurements, for VOC measurements, 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 VOCs; a VOC mixed gas sensor cannot detect CO
2
molecules.
TECHNICAL DATA
Power 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, relative humidity, air quality (VOC), carbon dioxide (CO
2
), atmospheric pressure
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. (non-precipitating air)
Deviation 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:
± 0.2 K at +25 °C
AIR QUALITY (VOC)
VOC sensor:
VOC sensor (metal oxide)
with automatic calibration
(VOC = volatile organic compounds)
VOC measuring range:
0...100 % air quality; with reference to calibration gas;
multi-range switching
VOC sensitivity low, medium, high
VOC measuring accuracy:
± 20 % final value (with reference to the calibration gas)
Service life:
> 60 months (under normal load conditions)
CARBON DIOXIDE (CO
2
)
CO
2
sensor:
Optical NDIR sensor (non-dispersive infra-red technology) incl. atmospheric air pressure compensation (up to 1100 mbar)
with automatic and manual calibration
CO
2
measuring range:
0...5000 ppm
CO
2
measuring accuracy:
± 30 ppm ± 3 % of measured value
CO
2
temperature dependence:
± 5 ppm ⁄ °C or ± 0.5 % of measured value ⁄ °C (whichever is the greater)
Pressure dependence:
± 0.13 % ⁄ mm Hg
Long-term stability:
< 2 % in 15 years
Gas exchange:
by diffusion
Bus parameters:
In the absence of current delivery
(under currentless conditions) can be
configured and addressed via DIP switch!
Bus interface:
RS 485,
galvanically isolated,
bus termination can be activated via DIP switch. Up to 32 devices possible in one segment.
In case of a greater number of devices, RS 485 transceivers must be used.
Bus protocol:
Modbus (RTU-Mode), address range 0...
247
selectable
Baud rate:
9600, 19200, 38400 Baud
Status indicator:
Green LED = Telegram valid / red LED = Telegram error
Signal filtering:
4 s / 32 s
Ambient temperature:
–10...+60 °C
Response time:
< 2 minutes
Electrical connection:
0.2 - 1.5 mm
2
, via push-in terminal
Enclosure:
plastic, UV-stabilised, material polyamide, 30 % glass-globe reinforced, with quick-locking screws (slotted ⁄
Phillips head combination), colour traffic white (similar to RAL 9016),,enclosure cover for display is transparent!
Enclosure dimensions:
126 x 90 x 50 mm (Tyr 2)
Cable gland: 2x
M 16 x 1.5; including strain relief, exchangeable
Protective tube:
KCO
2
/
KLQ - CO
2
/
KFTM - CO
2
/
KFTM - LQ - CO
2
- Modbus (Patent No. DE 10 2014 010 719.1):
PLEUROFORM
TM
, material: polyamide (PA6), with torsion protection, v
max
= 30 m/s (air), Ø 20 mm,
without filter: NL = 202.5 mm, with plastic sinter filter: NL = 235 mm (optional with metal sinter filter: NL = 227 mm)
AFTM - CO
2
/
AFTM - LQ - CO
2
- Modbus:
in stainless steel,
Ø 16 mm, with plastic sinter filter: NL = 55 mm (optional with metal sinter filter: NL = 47 mm)
Process connection:
channel sensors using a flange (included in the scope of delivery), on-wall sensors using screws
Protection class:
III (according to EN 60 730)
Protection type:
IP 65 (according to EN 60 529) enclosure only! (PLEUROFORM IP 30)
Standards:
CE-conformity, electromagnetic compatibility according to EN 61 326, EMC directive 2014 ⁄ 30 ⁄ EU
Optional:
three-line display with illumination,
cutout approx. 70 x 40 mm (W x H),
to display the actual humidity, actual temperature, air quality and / or the actual CO
2
content
