Capacitive electrodes EL 4 … 20 mA - compact
47
Diagnosis
Contact 4 against vessel
The connection between contact 4 and the metal vessel (not instrument
hexagon or electrode flange) should be as good as possible. Measure with
an ohmmeter (range very low) the resistance value between contact 4 and
the vessel.
• Shortcircuit (0␣ …␣ 3␣
Ω
), optimum connection
• Resistance >␣ 3␣
Ω
- corrosion on the mounting boss or flange
- probably the mounting boss was covered with Teflon tape or similar
Check the connection to the vessel. If there is no connection, you can
connect a line from the earth terminal outside to the vessel.
Note that coated flanges must be in any case connected via the earth
terminal to the vessel.
Contact 4 against 6
In case of values > 3
Ω
there is a defect.
When you cannot find a failure in the electrode, than exchange the
oscillator against a similar replacement type (if available) or send the
electrode for repair to VEGA.
After insertion of the new electronics, carry out an adjustment. See 4 Set-
up.
VVO-
failure message
Meas. value invalid
Measured value invalid
The actual measured value is not within the valid measuring range.
Reasons can be e.g. extreme modifications of the dielectric constant figure
or wrong adjustments.
Modify the actual measuring conditions.
