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8 Diagnosis, asset management and service
WIKA Operating Instructions - Differential pressure transmitter DPT-20
8 Diagnosis, asset management and service
8.1 Maintenance
If the device is used properly, no special maintenance is required in
normal operation.
In some applications, product buildup on the diaphragm can influence
the measuring result. Depending on the sensor and application, take
precautions to ensure that heavy buildup, and especially a hardening
thereof, is avoided.
The cleaning helps that the type label and markings on the instrument
are visible.
Take note of the following:
•
Use only cleaning agents which do not corrode the housings, type
label and seals
•
Use only cleaning methods corresponding to the housing protec-
tion rating
8.2 Diagnosis memory
The instrument has several memories available for diagnostic pur
-
poses. The data remain there even in case of voltage interruption.
Up to 100,000 measured values can be stored in the sensor in a ring
memory. Each entry contains date/time as well as the respective
measured value.
Depending on the instrument version, values that can be stored are
for example:
•
Level
•
Process pressure
•
Differential pressure
•
Static pressure
•
Percentage value
•
Scaled values
•
Current output
•
Lin. percent
•
Measuring cell temperature
•
Electronics temperature
When the instrument is shipped, the measured value memory is ac
-
tive and stores pressure value and measuring cell temperature every
10 s, with electronic differential pressure also the static pressure.
The requested values and recording conditions are set via a PC with
PACTware/DTM or the control system with EDD. Data are thus read
out and also reset.
Up to 500 events are automatically stored with a time stamp in the
sensor (non-deletable). Each entry contains date/time, event type,
event description and value. Event types are for example:
•
Modification of a parameter
Maintenance
Precaution measures
against buildup
Cleaning
Measured value memory
Event memory
