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In pressurized tanks the level has been measured for decades by differential
pressure transmitters and hydraulic pressure seals. Already several installer
generations have been forced to fight with the solution. The transport of the
measurement device - not to mention the installation without bending the
capillary - is a challenge, which frequently requires two installers and good
nerves.
The VDU transmitter developed by Satron is a significant innovation in
differential pressure measurements. Its principle is simple, an additional
sensor is connected to a two-wired 4..20 mA-transmitter electronics by an
electric cable. Both sensors are treated as separate measurements up to the
difference calculation. The maximum errors of both pressure measurements are the
same as in individual transmitters. In the difference calculation the maximum
error is nothing but doubled with respect to the individual sensor.
The installation is simple by means of Satron’s versatile coupling selection
and by pulling in the electric cable. PASVEŽ mounting valve is available for
uninterrupted service of the process. Hygienic couplings, through the use of
which the measuring diaphragm settles to the surface level, are appropriate for
sedimenting media. The other programmable, galvanically separated 4..20 mA
output available as an option for the VDU transmitter replaces the static
pressure transmitter cost-effectively.
The traditional differential pressure is still needed in applications, where
the static pressure is significantly higher than the differential pressure. In
VDU, the sensors are always dimensioned according to the highest prevailing
pressure, and in differential pressure according to the actual differential
pressure.
Typical items for VDU are also centrifugal cleaners, filters and screens, in
which the traditional pressure seal solution causes installation and cost
problems.
Traditional way of measuring the level and
static pressure of a pressurized tank
Satron VDU replaces the instruments in the
previous figure more precisely, more cost-effectively and in a more
installation-friendly way
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