Vega VEGAMET 624, Operating Instructions Manual

Page: 40 / 60

l
S
elect under "
R
eaction in case of failure " the option "
S
witching
condition o ff "
l
E nter the following values into the parameter fi elds :
-
M easured value more than
25
% / min .
-
M ax . reaction time
1
min .
T he function of the tendency recognition is shown in detail in the
following diagram . T he previously described example is used as a
basis .
t
t
m
t
m
t
m
t
m
120 180 240
ON
OFF
60
[sec]
1 2 3 4
5
...
... ... ...
100
75
50
25
0
%
...
F ig .
12
: E xample for tendency recognition
1
O ld average value =
25
% , new average value =
25
%
D i ff erence
<
25
%
-
>
R elay ON
2
O ld average value
=
25
%
, new average value
=
37
.
5
%
D i ff erence <
25
% - > R elay ON
3
O
ld average value =
37
.
5
%
,
new average value =
62
.
5
%
D i ff erence
=
25
%
-
>
R elay OFF
4
O ld average value =
62
.
5
% , new average value =
75
%
D i ff erence <
25
% - > R elay ON
5
tm -
>
max . reaction time
8
.
4
F low measurement
F or fl ow measurement in open fl umes , a contraction or standardised
fl ume must be used . D epending on the fl ow volume , this contraction
generates a certain backwater . T he fl ow can be determined from the
height of this backwater . T he fl ow volume is outputted by an
appropriate number of pulses on the relay or current output .
D
epending on the type and version
,
each fl ume generates a di ff erent
backwater . T he data of the following fl umes are available in the
instrument :
l
P almer - B owlus - F lume
l
V enturi fl ume , trapezoidal weir , rectangular weir
l
V - N otch
S etup
T he con fi guration of the fl ow measurement loop requires PACT ware
with the suitable DTM s . T he example refers to a fl ow measurement
with a radar sensor . T he following setup steps must be carried out :
F unctional principle
F
lume
40
VEGAMET
624
•
4
…
20
m A / HART signal conditioning instrument
8
A pplication examples
28969
-
EN
-
091116