Page
37 www.greyline.com
3.7.3
4. Select Off, to turn OFF the 4-20mA Output or
select one of the output ranges to turn it ON.
5. Press ENTER to return to the 4-20mA OUTPUT
screen.
4-20 mA OUTPUT
DD-MM-YY HH:MM:SS
Dim:
mm
Off
4-20mA
0-20mA
0-16mA
3.7.4 4-20mA signal calibration and ranging
Key Point:
The 4-20mA output has been calibrated in the factory and should not
require further adjustment. In the rare event that re-calibration is necessary, this
procedure should be carried out only by a trained engineer.
3.7.4
This procedure describes how to calibrate the 4-20mA output and ‘scale’ it to operate over a defined flow-rate
range.
Signal calibration
SETUP INSTRUMENT
DD-MM-YY HH:MM:SS
Dim:
mm
Set Date & Time : dd-mm-yy hh:mm:ss
Calibrate 4-20mA
Pulse output
Backlight
:
Disabled
Factory settings
Change Language
1. Select Setup Instrument from the MAIN MENU, to
access the SETUP INSTRUMENT screen.
2. Select Calibrate 4-20mA.
Exit
3. Connect a calibrated ammeter to the 4-20mA
output and adjust the UP/DOWN Scroll keys
(Coarse) and LEFT/RIGHT Scroll keys 5 & 6 (fine)
until the output is exactly 4.0mA.
The DAC should indicate approximately 8000.
4. Press ENTER when done.
CALIBRATE 4mA
DD-MM-YY HH:MM:SS
Dim:
mm
Adjust the output current to 4mA
Use
to set, 5/6 to trim
DAC Value: 8000
Press
when done
5. With the meter still connected to the 4-20mA output
adjust the Scroll keys to obtain an output of exactly
20mA.
The DAC should indicate approximately 40000.
6. Press ENTER when done.
CALIBRATE 20mA
DD-MM-YY HH:MM:SS
Dim:
mm
Adjust the output current to 20mA
Use
to set, 5/6 to trim
DAC Value: 40000
Press
when done