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3.3 4-20 mA Interface (optional)485Modbus interface
4-20mA interface wiring is shown in the table below.
Color
Function
Brown brown
4-20 mA positive
White
4-20 mA negative
If the equipment line mark is different from the 4-20 mA wiring table, the equipment
line mark shall prevail.
The corresponding relationship between the output current value and the turbidity
value is shown in the following table.
Relationship between current and turbidity values (type 31)
Current value
Turbidity values
4 mA
0NTU
X mA
[(x -4)/1.6] NTU
20 mA
20NTU
Relationship between current and turbidity values (type 30)
Current value
Turbidity values
4 mA
0NTU
x mA
[(x -4)/16] NTU
20 mA
1NTU
