46
NRG 26-60 - Installation & Operating Manual -
819875-00
System malfunctions
Faults during use
The measurement range limits 0 % and 100 % are obviously outside the sight glass level.
Possible causes if no error messages appear
Remedy
The measurement range has been set incorrectly.
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Check the calibration of the measurement range.
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Repeat the calibration if necessary.
The characteristic of the measurement signal in the measurement range is reproducible, but not linear.
Possible causes if no error messages appear
Remedy
The level electrode was install without a protective
tube.
The protective tube is required as a counter electrode.
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Install a protective tube.
The displayed measured value in the characteristic appears implausible when compared with the tendency of
the fill level in the sight glass.
Possible causes if no error messages appear
Remedy
The vent hole is blocked or flooded, or may be missing
entirely in certain circumstances.
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Check the protective tube
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Add a vent if necessary.
The stop valves of an external measuring cylinder
(option) are closed.
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Check the stop valves and open if necessary.
A long-operating and well-set electrode delivers increasingly inaccurate measured values.
Possible causes if no error messages appear
Remedy
Increasing contamination due to build-up of deposits
on the electrode rod.
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Remove the level electrode and clean the electrode rod
with a damp cloth.
A control unit, e.g. NRR2-60, signals a MIN or MAX alarm, although the fill level is still within the permitted
measurement range limits according to the sight glass.
Possible causes if no error messages appear
Remedy
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The measurement range is set incorrectly
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The electrode or protective tube is contaminated.
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Calibrate the measurement range at the operating point.
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Check the electrode and protective tube for contamina-
tion and clean if necessary.