Vega VEGAMET 841 - Configurable applications; Measurement loop settings (Damping, Linearisation)

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7 Set up with the integrated display and adjustment unit
VEGAMET 841 • 4 … 20 mA
58864-EN-200401
Thedeviceisconguredexworksforuniversalapplications.The
followingapplicationscanbechangedoverandconguredviathe
VEGA Tools app or the DTM:
•
Universal
•
Level storage tank
•
Pumping station
•
Sewage screw lifting station
•
Flowmeasurementume/weir
Information:
An overview of the available applications and functions can be found
in the appendix
The main menu is divided into four areas with the following functions:
•
Measuring point: Includes settings for adjustment, linearization,
scaling, relay outputs, …
•
Display: Contains settings for display of measured values
•
Extended functions: Includes settings for fail safe relay, access
protection, reset, …
•
Diagnosis Includes information on device type/status, …
7.4.1 Measurement loop
Tosuppressuctuationsinthemeasuredvaluedisplay,e.g.caused
by an agitated medium surface, an integration time can be set. This
time can be between 0 and 99 seconds. Remember that the reaction
time of the entire measurement will then be longer and the sensor will
react to measured value changes with a delay. In general, a period of
afewsecondsissucienttosmooththemeasuredvaluedisplay.
A linearisation is necessary for all vessels in which the vessel volume
does not increase linearly with the level, for example a horizontal
cylindrical or spherical tank. Corresponding linearisation curves are
preprogrammed for these vessels. They represent the correlation
between the level percentage and vessel volume. By activating the
appropriate curve, the volume percentage of the vessel is displayed
correctly. If the volume should not be displayed in percent but e.g. in l
or kg, a scaling can be also set.
Whensettingupaowmeasurement,alinearizationcurvesuitable
for the structural conditions must be selected. Corresponding curves
suchasventuri,triangularoverow,…areavailablehere.Inaddition,
individual, user-programmable linearisation curves can be stored via
DTM.
Through the adjustment the input value of the connected sensor is
converted into a percentage value. This conversion step allows any
input value range to be depicted in a relative range (0 % up to 100 %).
The percentage values can be used for presentation on the display,
for direct use in an output or for further conversion via linearization or
scaling.
When using the display and adjustment unit, the adjustment unit is
always "mA". When using PACTware/DTM or the VEGA Tools app,
Applications
Main menu
Damping
Linearisation
Adjustment