Vega MET 381 EX Mise En Service page 28

correspond to the actual filling levels must be
entered for the min. and max. adjustment. The
ideal calibration is at 0 % and 100 %. Because
it is not always possible to empty or fill a
vessel completely, any value can of course be
entered. The greater the difference between
the two adjustment points, the more precise the
measurement. It does not matter which value is
entered first.
→
Select position [B] or [C] on the function
switch, enter the percentage values for the
min. and max. adjustment and save your
settings.
Relay outputs
Two operating relays are integrated inVEGA-
MET 381 Ex for level detection. First of all,
determine at which switching points the relays
should switch on and off again. Furthermore you
have to distinguish between the relay modes
overfill and dry run protection. You switch over
by exchanging the ON/OFF values of the relay.
•
Overflow protection: Relay is switched
off when the max. level is exceeded (safe
currentless state), relay is switched on again
when the level falls below the min. level
(switch-on point < switch-off point)
•
Dry run protection: Relay is switched off
when the level falls below the min. level (safe
currentless state), relay is switched on again
when the max. level is exceeded (switch-on
point > switch-off point)
→
To adjust the on and off switching points of
relay 1, set the function switch to position
[1] or [2], enter the switching points for ON
or OFF and save your settings. If necessary,
proceed in the same way with relay 2 (posi-
tion [3] or [4]).
VEGAMET 381 Ex • 4 ... 20 mA signal conditioning instrument
6 Setup with the integrated display and adjustment unit
1
o n
2
o f f
o n
3
o f f
Abb. 17: Relay modes
1 Filling height
2 Mode overfill protection
3 Mode dry run protection
Scaling
Scaling means converting the measured value
into a certain parameter and unit. The indication
can then show the volume in litres e.g., instead
of the percentage value. Indication values from
-9999 to +9999 are possible.
1. First of all, determine the max. indicating
range and the number of decimal places
after the decimal point -- max. four decimal
places can be displayed. Select position [
5 ] of the function switch, place the decimal
point in the required position and save your
settings.
2. Now select position [6] or [7] on the function
switch, enter the requested values for
100 % or 0 % and save your settings.
Damping
To suppress fluctuations in the measured value
display, e.g. caused by an agitated product sur-
face, an integration time can be set. This time
can be between 0 and 250 seconds. Remember
that the reaction time of the entire measurement
will then be longer and the sensor will react
to measured value changes with a delay. In
general, a period of a few seconds is sufficient
to smooth the measured value display.
off (on)
on (off)
t
L E D
27