To increase application reliability, additional application diagnostics are now available for Krohne's H250 M40 variable area (VA) flowmeter in addition to the electronic device diagnostics. The new functions are implemented via intelligent software algorithms for signal analysis of the magnetic field sensors. The existing NE107 device diagnosis is thus extended to include VA specific application diagnostics: the device now detects, for example, blockages of the float caused by impurities in the medium or by strong, repeated pressure surges. Pulsations in liquid measurements with positive displacement pumps or compression oscillations in gas measurements are also detected. A message is also reported if the float is installed in the measuring cone upside down or is completely missing after maintenance or cleaning.
The signalling severity of the individual diagnostic functions can be configured according to NAMUR NE107 classes: from "for information" to "maintenance required" or "out of specification" to "failure" with activation of the failure current signal. The new functions not only increase application reliability, but also enable the measuring accuracy and service life of variable area flowmeters to be optimized with appropriate corrective measures. Existing devices can be retrofitted by exchanging modules in the field.