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Dinel DLS–27
Question
Answer / Solution
The sensor does not have sharp switching,
the connected relay grumbles.
Did you use the correct supply? It is necessary to use the source of
DC smoothing voltage (not only rectified pulsing voltage), the best
supply unit is Dinel or another suitable stabilized source.
The sensor does not have sharp switching,
the connected relay during the transfer
from one status to the other status grum-
bles despite the fact that the supply is OK.
Is the hysteresis set on the sensor correctly? It will be necessary
to increase the hysteresis by trimmer “H” (by turning in a clockwise
direction).
After the connection of the correct supply,
the sensor does not switch the load.
Did you select and connect the load correctly? Does the load have the
character of the bulb (very small resistance in inactive status) or does
it not contain higher capacitors? With the output it is only possible to
switch the resistance and inductive loads, see connection of sensors
(Fig. 13, 14, 15). Type of output PNP – the load is connected between
the output and zero potential. Type NPN – the load between the output
and the positive field of the supply.
After activation (filling, flooding), the sen-
sor does not switch..
Is the sensitivity of the sensor too high? The electronics of the sensor
are evidently only activated by the case (head) and the electrode or
remainders on the electrode. It is necessary to decrease the sensitivity
by trimmer “S“ (to turn in clockwise direction).
After connection of the supply, the sensor
is disconnected and is switched by
touching with the hand. Then, it will remain
permanently switched. It is necessary to
disconnect it from the source and connect
it again.
The sensor is evidently set so that it has too large hysteresis and the
change of the capacity after deactivation is insufficient for exceeding
the area of hysteresis and re-disconnection. It is sufficient to decrease
the hysteresis or to modify (decrease) the sensitivity so that the
sensor is able to achieve both marginal statuses – connection and
disconnection.
The sensor is disconnected from the side.
After installation, the sensor responded
to the conductive liquid several times, but
then responses stopped and it remained in
the activated status. The decrease of the
sensitivity did not help.
This mainly concerns the liquid which is able to create a continuous,
electrically conductive coat on the electrode (or the insulation). An
example of such liquids are some lye and alkaline washing detergents,
flushing water with metal content, etc. It is always necessary to test the
function or to select the assembly from upwards.
Does the dust badly affect the function of
DLS sensors?
No. The dust have almost no effect to function (as similar as dry
non-conductive adhered rests of material). The state of sensor
changes only when the mass of material covers the electrode. The
different situation is when the insulating bushing is covered by mixture
of condensed water and dust. These problems can be solved by type
choice of sensor and right sensitivity setting
Does the DLS sensor react on foams on
the level?
There exist various foams and capacitive sensors react on them
differently. When the base of foam is electrically conductive solution
(e.g. bear) we can DLS sensor use for foam detection, but it is
possible to make them on foams insensitive (by means of type choice,
sensitivity setting). The DLS sensors are generally insensitive on
foams from non-conductive liquids (plant oils)
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Summary of Contents for Dinel DLS-27 Series
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