The whole development
phase took a mere 1.5
years. To achieve this short
development time Heinrichs
Messtechnik utilized the
latest simulation technology.
Instead of mounting the coils onto the tubes, the manufacturer chose to mount them onto a
PCB situated between the measuring tubes. By simultaneously doubling the number of pick-up
coils from two to four, the resolution is increased significantly.
with tube diameters of 1.5 mm or less
present a significant weight, Heinrichs
Messtechnik adopted the following solution:
The conventional approach of mounting
the coils onto the tubes was abandoned in
favour their mounting on a printed circuit
board mounted between the tubes. This
method also enables the use of four sensor
coils instead of two, as is usually the case
with dual-tube Coriolis, providing a higher
resolution.
On the measuring tubes themselves only
very light magnets are mounted, which,
with a weight of only 0.08g, have little to no
influence on the vibrating behavior of the
tubes.
Instead of conventional brazing, the magnet
holders are mounted onto the tubes using
a special laser-welding technology. Utilizing
this method, Heinrichs Messtechnik aims at
keeping the production costs of the sensor
to an absolute minimum, it not only allows for
a stress‑free connection, but also eliminates
the time-consuming and elaborate process
of brazing in a vacuum oven.
INSENSITIVE TO EXTERNAL
INFLUENCES
Using the dual-tube design, the new HPC
displays extreme insensitivity towards
external influences, allowing for precise
measurements with a maximum deviation
of ± 0.1 Percent of the mean value and a
Zero-point stability between 0.001 and
0.005, making a mechanical decoupling
in most cases superfluous. Owing to the
measuring tubes high working frequency
of over 200 Hz, the coupling of installation
vibrations or similar oscillations into the
measuring system is prevented and so with
avoiding fault signals. A further advantage in
mounting the sensor coils on a motionless
PCB is the elimination of open wiring within
the sensor, as is the case of standard
commercially available devices. This wiring
often presents a vulnerable weak point,
since the wire and its point of connection
must vibration continuously with the
frequency of the measuring tubes.
With the exception of the laser welded
measuring tubes, the HPC consists
essentially of a solid drilled and tapped
stainless steel block. Furthermore, the
HPC has been stripped of a splitter at the
inflow of the tubes, instead possessing a
reservoir – in which the process pressure
distributes the fluid exact into the measuring
tubes, hence preventing flow disturbances
generally caused by splitters. This technique
has the timesaving advantage of one less
component to weld as well as one less
potential material stress source. The result
is an extremely robust device capable of
withstanding temperatures and pressures
of up to 180 °C and 600 bar respectively. “In
principle, the device may also be ordered
with Hastelloy tubes and other alloys”, added
Schramm.
VARIABLE ASSEMBLY CONCEPT
For flexible installations, different
constructive variations of the HPC are
available: Besides the traditional Inline
Version, which can be inserted directly into
the process line, there are three further
models available, which are suitable for
either wall mounting, by means of wall
brackets, or may simply be placed on a
table. “For our Table model there are two
available options: either with the measuring
pipes pointing downwards below the supply
line or pointing upwards above the supply
line. For the measurement of gas, upward
pointing tubes are recommended to prevent
any issues with fluid collecting in the tubes.
The same also goes visa versa for the
measurement of fluids”, Schramm remarks.
Collectively, the devices are available in
three measuring ranges:
0–20, 0–50 and 0–160 kg/h. On request
other adaptations are also available, for
example, customer-specific enclosures,
connectors or interfaces. In particular for the
chemical and semiconductor industry, fully-
welded stainless steel enclosures are also
available.
RAPID DEVELOPMENT SUCCESS
WITH HIGH-END SIMULATION
The whole development phase took a mere
1.5 years. To achieve this short development
time, Heinrichs Messtechnik utilized a state-
of-the-art simulation technology. “By these
means the required number of prototypes
was drastically reduced, reducing so with
development costs significantly”, Schramm
says contentedly. Furthermore, with the aid of
the simulation technology customer-specific
requirements can be captured and individual
solutions presented in the shortest of time.
The HPC was presented for the first time
on the Hannover trade fair from 23rd to
the 27th of April, simultaneously being the
official launch of sales. Furthermore, ATEX
and IECEx approvals are also planned
as well as a patent registration of the
technology. Parallel to the launch of sales,
Heinrichs Messtechnik is also working
on a new miniaturized transmitter with
flexible interfaces, specially designed for
compatibility with the HPC.
For further information, please visit www.kobold.com
Issue 44 PECM
69