Parker CDAS HL 050 - Page 32

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Medium Flow Compressed Air Dryers - IOMI.
Using the 4-20mA Signal
e calculation used to interpret the 4-20mA signal diers between the Parker Dewpoint Sensor (PDS) and Hygrometer.
Parker Dewpoint Sensor 4-20 mA output Dewpoint Calculation
PARKER DEWPOINT SENSOR
Current
mA
4 5 6 7 8 9 10 10.66 11 12 13 14 15 16 17 17.4 18 19 20
PDP
o
C
Out of Sensor Accuracy Range -50 -48 -40 -33 -25 -18 -10 -3 0
Out of Sensor
Accuracy Range
example:
measured value = 12mA
example:
measured value = 12mA
measure value = 14mA
measure value = 14mA
It should be noted that the accuracy of measured mA reects the accuracy of the Parker Dew Point Sensor ±4°C.
Hygrometer 4-20 mA output Dewpoint Calculation
PARKER DEWPOINT SENSOR
Current
mA
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
PDP
o
C
-100 -93 -85 -78 -70 -63 -55 -48 -40 -33 -25 -18 -10 -3 5 13 20
Dewpoint=((mA-4)×7.5)-100
((12-4)×7.5)-100=-40
((14-4)×7.5)-100=-25