VEGA Capacitive electrodes EK … with signal conditioning instrument - Manual (Page 33)

Capacitive electrodes EK with signal conditioning instrument 33
Diagnosis
b.Current value > 22 mA
- Check all connections and the connection line to the sensor.
- Should the red failure lamp continue to light, separate the sensor from
the connection line and connect instead a resistor of 2,2 kOhm.
When the failure lamp extinguishes, the sensor is defect. Check the
connected sensor.
- Should the failure lamp continue to light, connect the sensor again.
Separate the signal conditioning instrument from the connection line
and connect a resistor of 2,2 kOhm to the sensor input.
- Should the failure lamp continue to light, the signal conditioning instru-
ment is defect. In this case send the instrument to VEGA for repair.
- When the failure lamp extinguishes, this is perhaps a short-circuit in
the connection line. Check the connection line to the sensor.
Failure Measure, failure removal
Sensor defect, Test of the internal connections:
measurement does • Remove the housing cover.
not react to level • Loosen the three screws with a screwdriver and pull
changes the oscillator out of the housing. Use flat pliers to pull the
oscillator easily out of the housing. Hold the oscillator on the extension
of the separating wall between the sensor connections.
• Measure with an ohmmeter (range M
W) the resistance values be-
tween the following contacts:
C
M
- Capacitor
Screen