3-axis ultrasonic anemometer
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User manual
INSTUM_ 04861
Page
13/15
6
Maintenance
6.1
Testing
This type of testing is only required if the user wishes to verify the well functioning of each part of the
anemometer. Please note that these tests are not intended to establish the operational limitations of
the sensor.
Visual check
-
body of the anemometer is in a level position
-
there are no foreign objects in the transducer area
Operational check for 4÷20 mA output
To check the current output you need a multimeter and an air flow (you can use a hair dryer).
1.
Set the multimeter to measure signals in direct current (DC) and 20 mA scale.
2.
Referring to DISACC200074, connect the multimeter to the first output (wind speed) and power
on the anemometer.
3.
Place the sensor where there are not wind flows (0 m/s) and read 4 mA on the multimeter.
4.
Subject the sensor to the air flow and read a value grater then 4 mA on the multimeter.
5.
Connect the multimeter to the second output (wind direction).
6.
Subject the sensor to the air flows with the angles 0, 90, 180 and 270° checking the correspond-
ing current values as indicated in the following table:
Air flow provenience (°)
Output (mA)
0 (o 360)
4 (o 20)
90
8
180
12
270
16
7.
Connect the multimeter to the third output (elevation).
8.
Subject the sensor to the air flows from bottom to top and read a value between 12 and 20
mA on the multimeter.
9.
Subject the sensor to the air flows from top to bottom and read a value between 4 and 12
mA on the multimeter.
10.
Connect the multimeter to the fourth output (sonic temperature).
11.
Check that the output value is congruent with the ambient temperature. Below are the current
values based on some temperature values.
°C
mA
°C
mA
°C
mA
°C
mA
°C
mA
-4
9.76
4
11.04
12
12.32
20
13.60
28
14.88
-2
10.08
6
11.36
14
12.64
22
13.92
30
15.20
0
10.40
8
11.68
16
12.96
24
14.24
32
15.52
2
10.72
10
12.00
18
13.28
26
14.56
34
15.84
12.
Connect the multimeter to the fifth output (compass).
13.
Check that the output value is congruent with the value read by the anemometer. Below are the
current values based on some angle values.
