VEGA VEGACAP 82-98 - Manual (Page 35)

VEGACAP 35
Contact 4 to vessel
The electrical connection between contact 4 and the metal vessel (not
mounting boss or electrode flange) should be as good as possible.
Measure with an ohmmeter (range very low) the resistance value be-
tween contact 4 and the vessel.
• Shortcircuit (0 … 3
W), optimum connection
• Resistance > 3
W
- corrosion on the mounting boss or flange
- possibly the mounting boss was covered with Teflon tape or
something similar
Check the connection to the vessel. If there is no connection, you can
connect a line from the external grounding terminal to the vessel.
Make sure that coated flanges are always connected via the earth
terminal to the vessel.
Contact 7 to middle pin (1)
The resistance must be infinite (>10 M
W).
If the resistance is less, moisture has entered, or the compensation
capacitor or the phase shifting capacitor (CAP E31R) are defective.
Contact 3 to 4
On electrodes without screen the resistance is infinite (>10 M
W). On
VEGACAP 26, 27, 35 and 98 the resistance must be 1 M
W. In case of
lower values, the electrode insulation is defective or moisture entered
the instrument housing.
In case of higher values, a bonding failure in the adapter plate or a
defective resistor is likely the cause.
If you cannot detect a failure in the measuring probe, exchange the
oscillator with one of the same type (if available) or return the probe for
repair to VEGA.
If the failure does not disappear after inserting the new oscillator, you
have to carry out a new adjustment (because of production tolerances
of the oscillators).
Note:
Make sure when positioning the housing cover that the inspection glass
is above the control lamp (LED).
Diagnostics