Electronic differential pressure transmitter, Model DPT-EL
wikaDescription
In the process industry, differential pressure measurement
using primary and secondary circuits has several advantages
over conventional differential pressure methods. The measuring locations, which are usually several metres apart, are
connected via a flexible and easily routed cable. This eliminates the need for capillaries, which are complex to install
and susceptible to temperature changes.
Flexible configuration
Two identical or two different instruments can be combined.
The prerequisite is that one of the instruments is used as the
primary instrument.
This processes the measured values supplied by both
individual instruments. An internal calculation determines
the pressure difference and relays it to the controller via the
current loop or the bus system. The secondary instrument
only supplies the measured values to the primary instrument
via a bus line.
The possibilities for combination and the flexible connection
often enable a configuration in which diaphragm seals are no
longer needed for process separation. For example, a flush
system can be used at the bottom of the vessel, while an
open process connection in the upper part of the tank poses
no problem for measurement in the superimposed gas.
Insensitive to temperature fluctuations
Especially with vessels that are often outdoors, it is problematic when the sun shines on the capillaries. An increase in
pressure due to the effects of temperature often falsifies the
measuring result.
The cable used for electronic differential pressure measurement has almost no influence on the measuring result when
heated.
