16
G U
PREMASGARD
®
814x - Modbus
Rev. Data - V20
Maintenance-free microprocessor-controlled
PREMASGARD
®
814x - Modbus
(Series) with Modbus connection, in an impact-resistant plastic
housing with quick-locking screws, connection nozzles for pressure hose (Ø 6 mm / 0.236 in), plastic sinter filter (exchangeable), optionally with ⁄ with-
out display, to exactly detect the relative humidity (0…100% RH) and the temperature (–35...+80 °C / –31...+176 °F) in ducts and to measure the
differential pressure (max. ± 7000 Pa / ± 28 inWC) in air. International system of units SI (default) can be switched to Imperial (via Modbus). Incl.
mounting flange and connection set
ASD-06
(2 m / 78.74 in connecting hose, two pressure port nipples, screws).
The pressure sensor is applied to measure positive, negative or differential pressure in clean air and gaseous media. It is used in the clean room,
medical and filter technology, ventilation and air conditioning ducts, spray booths, large-scale catering facilities, for filter monitoring and level
measurement or for triggering frequency converters.
A long-term stable,
digital humidity and temperature sensor
and a
pressure sensor
with piezoresistive measuring element guarantee exact
measurement results. These measurands are used to internally calculate the following parameters that can be retrieved via Modbus: temperature,
relative humidity, dew point, absolute humidity, mixture ratio, enthalpy (ignoring atmospheric air pressure), differential pressure, volume flow, air
density.
Innovative Modbus sensor
with galvanically separated RS485-Modbus-interface, selectable bus termination resistance, DIP switch for setting the
bus parameters and bus address in current-free state, internal LEDs for telegram status display, two separate push-in terminals and large three-line
display (illuminated; with customised programming in the 7-segment and dot-matrix range). The sensor is factory-calibrated; an environmental precision
adjustment by an expert is possible.
TECHNICAL DATA
Power supply:
24 V AC (± 20 %) and 15...36 V DC
Power consumption:
< 4.8 W ⁄ 24 V DC typical; < 6.8 VA ⁄ 24 V AC typical
System of units:
SI
(default) or
Imperial
(switchable via Modbus)
Data points:
differential pressure [Pa] [inWC], volume flow [m
3
/h] [CFM], temperature [°C] [°F],
relative humidity [% RH], dew point [°C] [°F], absolute humidity [g/m
3
] [gr/ft
3
],
mixing ratio [g/kg] [gr/lb], enthalpy [kJ/kg] [Btu/lb], air density [kg/m
3
] [lb/ft
3
]
HUMIDITY & TEMPERATURE
Sensors:
digital humidity sensor with integrated temperature sensor,
low hysteresis, high long-term stability
Sensor protection:
plastic
sinter filter, Ø 16 mm / 0.63 in, L = 35 mm / 1.38 in, exchangeable
(optional
metal
sinter filter, Ø 16 mm / 0.63 in, L = 32 mm / 1.26 in)
Measuring range, humidity:
0...100 % RH
Operating range, humidity:
0...95 % RH (without dew formation)
Deviation in humidity:
typically
± 2.0 %
(20...80 % RH) at +25 °C / +77 °F, otherwise ± 3.0 %
Measuring range, temperature:
–35...+80 °C / –31...+176 °F
Deviation in temperature:
typically ± 0.2 K at +25 °C / ± 0.4 °F at +77 °F
PRESSURE
Type of pressure:
differential pressure
Pressure connection:
with
connection nozzles
for pressure hose Ø 6 mm / 0.236 in
(optional on request with
quick
connect for PVC fabric pressure hose Ø 6 mm / 0.236 in)
Measuring range, pressure:
–500
...
+500 Pa
/
–2.0
...
+2.0 inWC
or
–7000
...
+7000 Pa
/
–28
...
+28 inWC
depending on the type of device, see table
Accuracy, pressure:
Type 8148
(500 Pa / 2.0 inWC): typically ± 13 Pa at +25 °C / ± 0.05 inWC at +77 °F
Type 8147
(7000 Pa / 28 inWC): typically ± 105 Pa at +25 °C / ± 0.12 inWC at +77 °F
compared to the calibrated reference device
Above- ⁄ below-pressure:
max. ± 50 kPa / ± 200 inWC
Zero point offset:
± 10 % of final value
Hysteresis:
0.3 % of final value
Linearity:
< ± 1 % of final value
Temp. drift values:
± 0.1 % per °C ⁄ °F
Long-term stability:
± 1 % per year
Medium:
clean air and non-aggressive, non-combustible gases
Media contacting parts:
Brass, Ni, thermoset plastic, Si, epoxy, RTV, BSG, UV silicone gel
Media temperature:
–20...+50 °C / –4...+122 °F (temperature-compensated 0...+50 °C / +32...+122 °F)
Continued on next page!
