VEGA Capacitive electrodes EK 4 … 20 mA - Compact - Manual (Page 26)

26 Capacitive electrodes EK 4 … 20 mA - Compact
22574-EN-020809
Setup
If you want to assign a certain current value to
a known level, you can modify the current with
the plus and minus keys. Each push of the
key changes the current value by a 10 µA
increment.
If you hold the key pushed, the values
changes with rising speed.
Example: If you know that your vessel is filled
up to 90 % and will be completely full at
100 %, then you can enter under max. adjust-
ment a value of 18.4 mA.
20 mA - 4 mA = 16 mA
16 mA * 90% = 14.4 mA
14.4 mA + 4 mA = 18.4 mA
We recommend that you connect an ammeter.
See 3.2 Electrical connection. By doing this,
you can monitor the current value during
modification. If you hold the key pushed, the
value changes automatically and with rising
speed. The difference between min. and max.
adjustment should be at least 20% or 3.2 mA.
(+/-) set 20 mA
(+) increase current
(-) reduce current
3 Integration time
If you want to set the integration time (damp-
ing), you have to set the rotary switch to posi-
tion 3. With the plus and minus keys you can
double or halve the value of the integration
time step by step. As a standard feature, an
integration time of 0.5 seconds is set. Count
how often you push the key so that you can
set the time correctly. In case of doubt, you
can reset the integration time to the preset
value of 0.5 s by pushing both keys simulta-
neously. Then you repeat the setting. After the
set integration time has expired,
63 % of the measured value change is trans-
mitted to the output.
The following integration times can be selected
on the oscillator: 0.5; 1; 2; 4; 8; 16; 32; 64;
128; 256 (s)
(+/-) 0.5 s
(+) increase time
(-) reduce time
Example: To set an integration time of 8 sec-
onds, you have to push the „+“ key 4 times.
4 Reverse characteristics
With this function you can reverse the charac-
teristics of the current output. The reverse is
also shown on the ammeter.
(+/-) 4 ... 20 mA
(-) 4 ... 20 mA
(+) 20 ... 4 mA
5 Linearisation
With this function you can activate the saved
linearisation curve. As a standard feature, the
curve for a cylindrical tank is contained in
memory. With CAP E 32 H you can enter other
linearisation curves via VVO. In this case,
presetting the oscillator is not necessary.
(+/-) Linearisation Off
(+) Linearisation ON
(-) Linearisation Off
6 Sensor optimisation
Mode 1 = Phase angle 90° Mode 1 = Phase angle 90° Mode 1 = Phase angle 90° Mode 1 = Phase angle 90° Mode 1 = Phase angle 90°
Mode 1 is a pure capacitance measurement,
the ohmic conductance is not taken into ac-
count in the measuring result. t
Application:
- standard setting
- non-conductive liquids up to approx.
50 µS
- compensation of conductance changes in
liquids
- generally with partly insulated electrodes in
liquids
- non-conductive solids without moisture
content
- with insufficient product grounding
- with electrodes in conjunction with a concen-
tric tube
- in non-conductive vessels with exterior
ground surface