VEGA Conductive electrodes - Manual (Page 31)

Conductive measuring system 31
Pump control, mode B
Dry run protection (channel 1)
Pre-requirements
- First of all connect only the mass and the
max. electrodes to the signal conditioning
instrument (connection points d28 and
d30)
- Set the selection switch of channel 1 (16) to
mode B
- Connect the signal conditioning instrument
to power supply
- Turn the potentiometer (5) to position 10
Adjust switch point
- Fill the vessel until the max. electrode is
covered by approx. 1 cm
- Turn the potentiometer (5) slowly
anticlockwise until the yellow LED of
channel 1 extinguishes
- Now connect the min. electrode to the
connection point d32 of the signal
conditioning instrument
The pump control is adapted to the product
conductivity, i.e. the relay of output 1
energizes at max. level and the transistor of
output 1 is conductive.
This switching condition remains until the level
decreases the position of the min. electrode,
i.e. the relay of output 1 deenergizes at min.
level and the transistor of output 1 blocks.
Only at max. level the relay of output 1
energizes again and the transistor of output 1
is conductive.
These set-up examples relate to channel 1,
the same procedure is valid for channel 2.
Set-up VEGATOR 532 Ex
Note
For all switch point adjustments it must be
generally noted that between reaching of the
switch point and triggering of the switching
function an integration time of 0,5 s is
effective. The potentiometer must therefore
be turned slowly.
In all applications in conjunction with an inte-
gral resistor of 220 kOhm a line monitoring of
the mass and max. electrode must be
guaranteed.