Commissioning
Proline Promag 55 FOUNDATION Fieldbus
74
Hauser
Activating warnings
All diagnostic parameters can be assigned a limit value if necessary. If this limit value is exceeded,
a warning is activated
→
WARNING MODE (7503) function.
The limit value is input into the measuring system as an absolute (+/–) or relative deviation
compared to the reference value
→
WARNING (75....) function.
Deviations which occur and which are recorded by the measuring system may also be output via
the current or relay outputs.
Interpretation of data
The interpretation of data records recorded by the measuring system greatly depends on the
application in question. This requires that the users have an exact knowledge of their process
conditions and the associated deviation tolerances in the process. In individual cases, these must be
determined by the users themselves.
For example, in order to use the limit function, a knowledge of the permitted minimum and
maximum deviation tolerances is of particular importance. Otherwise, there is the risk that a
warning may be activated unintentionally in the case of "normal" process fluctuations.
Deviations from the reference status can happen for different reasons. The following table contains
examples and notes for each of the six diagnostic parameters recorded:
!
Note!
In order to assess the possible formation of buildup, the diagnostic parameters of the COATING 1
and COATING 2 function groups must be interpreted and evaluated only in conjunction with those
under ELECTRODE POTENTIAL 1 and 2 and VOLUME FLOW. As the buildup typically develops
over a period of months, it is useful to present and evaluate the relevant measured data and
parameters using suitable software – for example using the Hauser software package
"FieldCare" with the Flow Communication FXA193/291 DTM and Fieldsafe Module.
Function group
(diagnostic parameters)
Possible causes of deviations from the reference value
COATING 1
A deviation from the reference value may be caused by the following:
• Formation of buildup on measuring electrode 1
• Electrical interruption
• Short-circuit
COATING 2
A deviation from the reference value may be caused by the following:
• Formation of buildup on measuring electrode 2
• Electrical interruption
• Short-circuit
ELECTRODE POTENTIAL 1
A change in the electrode potential may be caused by the following:
• Corrosion processes on measuring electrode 1
• Stronger fluctuations in the pH of the fluid
• Formation of air bubbles on measuring electrode 1
• Mechanical shocks to the measuring electrode due to solids
• Electrical interruption
• Short-circuit
ELECTRODE POTENTIAL 2
A change in the electrode potential may be caused by the following:
• Corrosion processes on measuring electrode 2
• Stronger fluctuations in the pH of the fluid
• Air bubbles on measuring electrode 2
• Mechanical shocks to the measuring electrode due to solids
• Electrical interruption
• Short-circuit
VOLUME FLOW
The volume flow is additional information that is required in order to be able to assess
the other diagnostic parameters sufficiently.
NOISE VALUE
A change in the noise value may be caused by the following:
• Corrosion processes on the measuring or reference electrodes
• Air bubbles
• Mechanical shocks to the measuring electrodes due to solids
