12
User Manual EE850 Duct Sensor
Decoding of floating point values:
Floating point values are stored according IEEE 754 standard. The byte pairs 1, 2 and 3, 4 are inverted
as follows:
MMMMMMMM
MMMMMMMM
SEEEEEEE
EMMMMMMM
Byte 3
Byte 4
Byte 1
Byte 2
Example:
Response [Hex]
Decimal value
Byte 1 (Register 2 - Hi) Byte 2 (Register 2 - Lo) Byte 3 (Register 1 - Hi) Byte 4 (Register 1 - Lo)
44
A1
0B
00
1288.34375
4 Technical Data
Measurands
CO
2
Measurement principle
Dual wavelength non-dispersive infrared technology (NDIR)
Measuring range
0...2000 / 5000 / 10000 ppm
Accuracy at 25 °C
(77 °F)
0...2000 ppm:
< ± (50 ppm +2% of measured value)
and 1013 mbar
(14.7 psi)
0...5000 ppm:
< ± (50 ppm +3% of measured value)
0...10000 ppm:
< ± (100 ppm +5% of measured value)
Response time t
63
< 100 s at 3 m/s
(590 ft/min)
air speed in the duct
Temperature dependency, typ.
± (1 + CO
2
concentration [ppm] / 1000) ppm/°C, for -20...45 °C
(-4...113 °F)
Calibration interval
1)
> 5 years
Measuring interval
Approx. 15 s
Temperature
Working range
-20...60 °C
(-4...140 °F)
Accuracy at 20 °C
(68 °F)
± 0.3 °C
(± 0.54 °F)
Response time t
63
< 50 s
Relative Humidity
Working range
0...95 % RH
Accuracy at 20 °C
(68 °F)
± 3 % RH (20...80 % RH)
Response time t
63
< 10 s
Outputs
Analogue
CO
2
: 0...2000 / 5000 / 10000 ppm
0 - 5 V / 0 - 10 V
-1 mA < I
L
< 1 mA
4 - 20 mA
R
L
< 500 Ohm
T
scale: according ordering guide
0 - 5 V / 0 - 10 V -1 mA < I
L
< 1 mA
RH
scale: 0...100 % RH
Digital Interface
RS485
EE850 = 1/10 unit load
Protocol
Modbus RTU or BACnet MS/TP
Passive temperature,
2-wire
T sensor type according ordering guide
Wire resistance (terminal - sensor), typ. 0.4 Ω
General
Power supply class III
24 V AC/DC ± 20 % 15-35 V DC
Current consumption average
Typ. 15 mA + output current
peak
Max. 350 mA for 0.3 s
Minimum air speed in the duct
1 m/s
(196 ft/min)
Enclosure material
Polycarbonate, UL94V-0 approved
Protection class
Enclosure: IP65 / NEMA 4
Probe: IP20
Cable gland
M16 x 1.5
Electrical connection
Screw terminals max. 2.5 mm
2
(AWG 14)
Electromagnetic compatibility
EN61326-1 EN61326-2-3 Industrial Environment
FCC Part 15 ICES-003 ClassB
Working and storage conditions
-20...60 °C
(-4...140 °F)
0...95 % RH (non-condensing)
1) under normal operating conditions
