Vaisala WMT700 - Manual (Page 55)

Chapter 3 _______________________________________________________ Functional Description
NOTE The scaling of the current output 4…20 mA depends on the sensor
measurement range (WMT701, WMT702, or WMT703), while the
0…20 mA output has 0.2 mA / m/s scaling for all the measurement
ranges.
Table 20 and Table 21 below list the most common settings for
different units.
Table 20 Common Transfer Function Settings for
AOUT1 (WS)
Output Signal Scaling/Units Setting for Gain Setting for Offset
Voltage 8 mV / mph
100 mV / m/s 0.017895
0.1 0
0
Current 0.2 mA / m/s 0.0002 0
Frequency 5 Hz / mph
10 Hz / m/s 11.185
10 0
WS425 - voltage 8 mV / mph 0.017895 0
WS425 - frequency 5 Hz / mph 11.185 0
Table 21 Common Transfer Function Settings for
AOUT2 (WD)
Output Signal Scaling/Units Setting for Gain Setting for Offset
Voltage 4 mV / °
20 mV / ° 0.004
0.02 0
0
Current 50 uA / degree 0.00005 0
Potentiometer 359° = Aout ref 0.0027855 0
You can configure output scaling or transfer function settings in a
variety of ways by changing the custom gain and offset. The basic
measurement units are m/s and degrees. The physical output units
are V, A, and Hz. For the potentiometer, an output of 1 means
100% of the Aout ref voltage.
The following formula illustrates the impact of gain and offset
values on the produced output:
o = y0 + k×s
where
o = Produced analog output (V, A, Hz, 100%)
s = Measured wind speed or direction (in m/s or °)
k = Selected gain value
y0 = Selected offset value
VAISALA ________________________________________________________________________ 53