User manual for - FLOW METER SPP-N118
Cutoff Threshold “CT” is defined by formulas below:
CT
=
" CutoFF"
×
20mA
100
for
0
÷
20
mA
output
CT
=
" CutoFF"
×
16mA
100
4
mA
for
4
÷
20
mA output
“Lo r”
,
”Hi r”
- These parameters define the expansion of nominal range in percent. They
determine the permissible range of input currents (Figure7.1).
The permissible range allow user to exceed the nominal range of input current.
If input value is contained in the permissible range a proper result is displayed.
If input current exceeds this range (defined by
“Lo r”
and
“Hi r”
),
“-Lo-”
or
“-
Hi-”
warning
is displayed
depend on input current value.
Figure 7.1 Example of definition of permissible range of input currents -
“
Lo r
” and “
Hi r
” parameters (
“4-20”
mode)
The
“Lo r”
parameter is important if input is set to
“4-20”
mode only, and
determines lower border of the permissible range. If input is set to
“0-20”
mode,
lower border of the permissible range is always 0mA.
If input is set to
“4-20”
mode, the lower border is calculated due to expression:
I
min
= 4 mA - 4 mA ×
“Lo r”
%.
The
“Lo r”
value can be set from 0 to 99.9%.
Parameter
“Hi r”
determines the upper border of the permissible range accordingly
to the expression (for both
“0-20”
i
“4-20”
modes):
I
max
= 20 mA + 20 mA ×
“Hi r”
%.
32
”
Lo r
” = 75,0% (3 mA)
”
Hi r
” = 5,0 % (1 mA)
4
21
permissible measurement range
measurement result is displayed
regardless on nominal range exceeding
nominal measurement range (4-20mA)
[ mA ]
20
22
1
0
I
min
I
max
display
message ”
-Lo-
”
display
message ”
-Hi-
”
