VEGA PULS45 User Manual
Operating Instructions
VEGAPULS 42, 44 and 45 – VBUS
Level and Pressure
Contents
Safety information ........................................................................ 3
Note Ex area ................................................................................ 3
1 Product description
1.1 Function................................................................................. 4
1.2 Application features ............................................................. 6
1.3 Adjustment ............................................................................ 6
2 Types and versions
2.1 Overview .............................................................................. 9
2.2 Type code........................................................................... 11
2.3 Antennas............................................................................. 12
3 Mounting and installation
3.1 General installation instructions ........................................ 14
3.2 Measurement of liquids ..................................................... 16
3.3 Measurement in standpipe (surge or bypass tube) ...... 18
3.4 False echoes ...................................................................... 25
3.5 Installation mistakes ........................................................... 27
Contents
4 Electrical connection
4.1 Connection and connection cable .................................... 30
4.2 Connection of the sensor .................................................. 33
4.3 Connection of the external indicating instrument
VEGADIS 50 ....................................................................... 34
4.4 Configuration of measuring systems ............................... 35
2 VEGAPULS 42, 44 and 45 – VBUS
Contents
5Setup
5.1 Adjustment structure ......................................................... 42
5.2 Adjustment with the PC on the signal
conditioning instrument ...................................................... 43
5.3 Adjustment with VEGAMET or MINICOM ........................ 69
5.4 Adjustment with the PC on VEGALOG ............................ 76
6 Diagnosis
6.1 Simulation ............................................................................ 82
6.2 Error code .......................................................................... 82
7 Technical data
7.1 Data ..................................................................................... 83
7.2 Approvals ........................................................................... 88
7.3 Dimensions ......................................................................... 89
Safety information
Please read this manual carefully, and also take
note of country-specific installation standards
(e.g. the VDE regulations in Germany) as well
as all prevailing safety regulations and accident prevention rules.
For safety and warranty reasons, any internal
work on the instruments, apart from that involved in normal installation and electrical connection, must be carried out only by qualified
VEGA personnel.
VEGAPULS 42, 44 and 45 – VBUS 3
Note Ex area
Please note the attached safety instructions
containing important information on installation
and operation in Ex areas.
These safety instructions are part of the operating instructions and come with the Ex approved instruments.
1 Product description
Product description
VEGAPULS series 40 sensors are a newly
developed generation of very compact, small
radar sensors for high resolution and accuracy. They are characterised by special
focusing features for level measurement in
narrow space applications. With modest
space requirements they were developed for
measuring distances of 0 … 4 m/10 m/20 m
and for standard applications such as storage vessels and buffer tanks as well as for
process tanks. With small housing dimensions and process fittings, the compact sensors monitor your levels at reasonable cost.
With the integrated display they enable high
precision level measurements and due to
their advantages, radar sensors have
increasingly become the standard solution
for many applications, even for those where it
was previously unthinkable due to high
costs.
VEGAPULS 40 radar sensors utilise two-wire
technology perfectly. The supply voltage and
the output signal are transmitted via one twowire cable. They provide a digital output
signal (VBUS or Profibus) or an analogue
4 … 20 mA signal as output or measuring
signal.
This operating instruction manual relates
to VEGAPULS 42, 44 and 45 sensors with
digital VBUS output signal (VEGA-Bus).
1.1 Function
Radio detecting and ranging: Radar.
VEGAPULS radar sensors are used for noncontact, continuous distance measurement.
The measured distance corresponds to a
filling height and is outputted as level.
Measuring principle:
emission – reflection – reception
Tiny 26 GHz radar signals are emitted from
the antenna of the radar sensor as short
pulses. The radar impulses reflected by the
sensor environment and the product are
received by the antenna as radar echoes.
The running period of the radar impulses
from emission to reception is proportional to
the distance and hence to the level.
Meas.
distance
emission - reflection - reception
The radar impulses are emitted by the antenna system as pulse packages with a
pulse duration of 1 ns and pulse intervals of
278 ns; this corresponds to a pulse package
frequency of 3.6 MHz. In the impulse intervals, the antenna system operates as receiver. Signal running periods of less than
one billionth of a second must be processed
and the echo image evaluated in a fraction of
a second.
1 ns
278 ns
Pulse sequence
4 VEGAPULS 42, 44 and 45 – VBUS
Product description
VEGAPULS radar sensors can accomplish
this through a special time transformation
procedure which spreads out the more than
3.6 million echo images per second in a slowmotion picture, then freezes and processes
them.
tt
Time transformation
Hence, it is possible for the VEGAPULS radar sensors to process the slow-motion
pictures of the sensor environment precisely
and in detail in cycles of 0.5 to 1 second
without using time-consuming frequency
analysis (e.g. FMCW, required by other radar
techniques).
Virtually all products can be measured
Radar signals are physically similar to visible
light. According to the quantum theory they
propagate through empty space and are
therefore not dependent, like e.g. sound
waves, on a conductive medium. And like all
electromagnetic waves, they travel at the
speed of light.
The radar signals react to two primary
electrical properties:
- the electrical conductivity of a substance.
- the dielectric constant of a substance.
All products which are electrically conductive
or have a dielectric constant greater than ε
1.6 have sufficiently good reflection charac-
r
teristics for reliable radar measurement.
(Note: air has a dielectric constant ε
The signal reflection increases with the con-
of 1).
r
ductivity or with the dielectric constant of the
product. Therefore virtually all products can
be measured.
%
50
40
30
20
10
5 %
5
0
2
4 6 8 12 14 16 18
0
25 %
10
40 %
20
ε
r
Reflected radar power dependent on the dielectric
constant of the measured product
With standard flanges between DN 50 and
DN 150, ANSI 2" to ANSI 6" or G 1½ A and
1½" NPT the sensor antenna systems are
adapted to the various products and measuring environments.
High quality materials withstand also extreme
chemical and physical conditions. The sensors deliver reliable, precise and long-term
stable, reproducible level signals.
Continuous and reliable
Unaffected by temperature, pressure and
individual gas atmospheres, VEGAPULS
radar sensors are used for quick and reliable
continuous level measurement of various
products.
%
0,03
0,02
0,01
0
100 500 1000 1300 ˚C
0
0,018 %
Temperature influence: Temperature error absolutely
zero (e.g. at 500°C 0.018 %)
%
10
5
0,29 %
0
10
0
1,44 %
20 30 40 60
50
Pressure influence: Error with pressure increase very
low (e.g. at 50 bar 1.44 %)
0,023 %
2,8 %
70 80 90 110 120 130 140
100
3,89 %
bar
VEGAPULS 42, 44 and 45 – VBUS 5
Product description
1.2 Application features
Applications
• Level measurement of all liquids.
• Measurement also in vacuum.
• All slightly conductive substances and all
substances with a dielectric constant > 2.0
can be measured.
• Measuring range 0 … 10 m (type 42).
Measuring range 0 … 20 m (type 44).
Measuring range 0 … 4 m (type 45).
Two-wire technology
• Power supply and output signal on one
two-wire cable (loop powered).
• VBUS output signal (VEGA-Bus).
Rugged and wear-free
• Non-contact.
• High resistance materials.
Exact and reliable
• Accuracy 0.05 %.
• Resolution 1 mm.
• Unaffected by noise, steam, dust, gas
compositions and inert gas stratification.
• Unaffected by varying density and temperature of the medium.
• Measurements of pressures up to 40 bar
and temperatures up to 150 °C.
1.3 Adjustment
Each measuring situation is unique. For that
reason, every radar sensor needs some
basic information on the application and the
environment, e.g. which level means "empty"
and which level "full". Beside this "empty and
full adjustment", many other settings and
adjustments are possible with VEGAPULS
radar sensors.
Adjustment and parameter setting of the
radar sensors is done with
- the PC and the adjustment program VVO
- the detachable adjustment module
MINICOM
- the VEGAMET signal conditioning instrument
Adjustment with the PC
Setup and adjustment of the radar sensors is
generally done on the PC with the adjustment
program VEGA Visual Operating (VVO)
under Windows
graphics and process visualisation, the program leads you quickly through adjustment
and parameterisation.
®.
By means of pictures,
Communicative
• Integrated display of measured values.
• Optional display separate from the sensor.
• Adjustment with detachable adjustment
module which can be plugged into the
sensor or into the external display.
• Adjustment with signal conditioning instrument.
• Adjustment with PC.
Approvals
The adjustment program recognises the sensor type
• CENELEC, ATEX, PTB, FM, CSA, ABS,
LRS, GL, LR, FCC, RINA.
Visualised creation of a vessel linearisation curve
6 VEGAPULS 42, 44 and 45 – VBUS
Product description
Note:
The adjustment program VVO must be available in version 2.70 or higher.
The PC can be connected to any position of
the system or the signal cable. It is connected with the two-wire PC interface converter VEGACONNECT 2 to th e sensor, the
signal cable or the signal conditioning instrument. The sensor is connected directly to the
VEGALOG processing system with the
standard cable (RS 232).
2
2
Adjustment with the PC on the digital signal and
supply cable between sensors and VEGAMET signal
conditioning instrument or directly on the sensor
2
…
…
1 ... 15
CPU
VEGALOG
VEGALOG
571 CPU
571 EA
Adjustment on the digital signal and supply cable to
the VEGALOG 571 processing system or directly on
the sensor
The adjustment and parameter setting data
can be saved on the PC with the adjustment
software and protected by passwords. The
adjustments can be quickly transferred to
other sensors if required.
2
......
CPU
2
1...15
VEGALOG
VEGALOG
571 CPU
571 EA
2
Adjustment with the PC on the VEGALOG processing
system with standard cable RS 232 (up to 15 sensors
can be operated on one two-wire cable with the
processing system)
Adjustment with the PC on the VEGAMET signal
conditioning instrument, to which one or two sensors
can be connected
VEGAPULS 42, 44 and 45 – VBUS 7
Product description
Adjustment with adjustment module
MINICOM
With the small (3.2 cm x 6.7 cm) 6-key adjustment module with display you carry out
the adjustment in clear text dialogue. For this
purpose, the adjustment module can be
plugged into the radar sensor or into the
optional external indicating instrument.
Tank 1
m (d)
12.345
Detachable adjustment module MINICOM
Unauthorised sensor adjustments can be
prevented by removing the adjustment module.
ESC
+
-
Tank 1
m (d)
OK
12.345
2
ESC
+
-
Tank 1
m (d)
OK
12.345
4
ESC
+
-
OK
%
100
+
-
OK
ESC
CONNECT
!
on
513
Adjustment with the VEGAMET signal
conditioning instrument
The radar sensors with digital output signal
can be adjusted, besides with the PC, also
with the VEGAMET signal conditioning instrument.
%
100
+
-
OK
ESC
CONNECT
12
!
on
515V
6-key adjustment field on the instrument front of the
VEGAMET signal conditioning instrument
For adjustment, the digital VEGAMET 514V
and 515V signal conditioning instruments are
provided with a 6-key adjustment field with
display. Here you can carry out the parameter setting in clear text dialogue. Using the
6-key adjustment field, it is also possible to
adjust one or two connected sensors with the
signal conditioning instrument. The
adjustment scheme corresponds to that of
the adjustment module MINICOM.
Adjustment with detachable adjustment module. The
adjustment module can be plugged into the radar
sensor or into the external indicating instrument
VEGADIS 50.
8 VEGAPULS 42, 44 and 45 – VBUS
Types and versions
2 Types and versions
2.1 Overview
Series 40 sensors are manufactured in three
basic versions, VEGAPULS 42, VEGAPULS
44 and VEGAPULS 45.
VEGAPULS 42 sensors are characterised by
1
G 1
/2 A or 11/2" NPT thread as process fitting.
These sensors are equipped as standard
versions with a ø 40 mm horn as antenna.
VEGAPULS 44 sensors are characterised by
a DIN or ANSI flanges as process fitting. In
standard version they are manufactured with
DN 50, 80, 100 and 150 as well as with ANSI
2", 3", 4" and 6". The bigger flanges come
equipped with respectively larger antenna
horns (ø 48, 75 and 95 mm).
Generally: The bigger the antenna horn, the
better the focusing characteristics, and the
better the antenna gain. This ensures that
even a weak product echo can be detected
reliably as level echo.
VEGAPULS 45 sensors come completely
equipped with a measuring tube of 4 m
length. These sensors are used in
applications where high accuracy is required
or for liquids with very low dielectric constant
such as e.g. liquid gas.
VEGAPULS 42
VEGAPULS 45
with thread
G 1½ A or 1½"
NPT
VEGAPULS 44
VEGAPULS 45
with flange
VEGAPULS 42, 44 and 45 – VBUS 9
Types and versions
Features
General features
• Measurement preferably of liquids in storage tanks or process vessels with increased
accuracy requirement.
• Measuring range 0 … 4 m, 0 … 10 m or 0 … 20 m.
• Ex approved in Zone 1 (IEC) or Zone 1 (ATEX) classification mark
EEx ia [ia] IIC T6.
• Integrated display of measured values.
Overview
PS42XXE… PS44XXE… PS45XXXE…
Signal output
- VBUS (VEGA-Bus) • • •
Antenna
- horn antenna • • –
- pipe antenna
1) 1)
•
Process fitting
- G 1½ A; 1½" NPT • – •
- DN 50; ANSI 2" – • •
- DN 80; ANSI 3" – • •
- DN 100; ANSI 4" – • •
- DN 150; ANSI 6" – • •
Adjustment
-PC •••
- adjustment module in the sensor • • •
- adjustment module in external
indicating instrument • • •
- with signal conditioning instrument • • •
Measuring range 0 … 4 m
- ø 40 mm horn 0 … 10 m – (depending on the
- ø 48 mm horn 0 … 15 m 0 … 15 m tube length)
- ø 75 mm horn 0 … 20 m 0 … 20 m
- ø 95 mm horn 0 … 20 m 0 … 20 m
1)
When mounting on a standpipe or bypass tube, a pipe antenna is created. The tube inner diameter should be
between 40 mm and 80 mm.
10 VEGAPULS 42, 44 and 45 – VBUS
Types and versions
2.2 Type code
PS 42 .XX X X X XXX X X
K - Plastic housing PBT, M20 x 1.5 cable entry
N - Plastic housing PBT, ½" NPT cable entry
A - Aluminium housing, M20 x 1.5 cable entry
D - Aluminium housing, ½" NPT cable entry in Exd connection
housing
V - Seal of the antenna system: Viton
A - Seal of the antenna system: Kalrez
G - Process fitting G 1½
N - Process fitting 1½" NPT
A
ABC- Process fitting DN 50 PN 40
BBE- Pr ocess fitting DN 80 PN 40
CBG-Process fitting DN 100 PN 16
DBG-Process fitting DN 150 PN 16
ARC- Process fitting ANSI 2" 150 psi
BRE- Pr ocess fitting ANSI 3" 150 psi
CRG-Process fitting ANSI 4" 150 psi
DRG-Process fitting ANSI 6" 150 psi
YYY- Process fitting on request
X - without display
A - with integrated display
X - without adjustment module MINICOM
B - with adjustment module MINICOM (mounted)
B - 20 … 72 V DC; 20 … 250 V AC; 4 … 20 mA, HART
(four-wire)
D - Two-wire (loop powered), 4 … 20 mA, HART
®
®
E - Power supply via signal conditioning instrument
G - Segment coupler for Profibus PA
XX - FTZ (standard telecommunication approval Germany)
AX - Approval in Ex-Zone 1, EEx ia IIC T6
CX - Approval in Ex-Zone 0, EEx ia IIC T6
BX - Approval in Ex-Zone 1 (Exd connection housing)
DX - Approval in Ex-Zone 0 (Exd connection housing)
Type 42: with screwed process fitting
Type 44:Instrument series with flange connection
Type 45: with measuring tube
PS: Radar sensors series 40
VEGAPULS 42, 44 and 45 – VBUS 11
Types and versions
2.3 Antennas
The antenna is the eye of the radar sensor. A
casual observer would never guess how
carefully the antenna geometry must be
adapted to the physical properties of electromagnetic fields. The geometrical form determines focal properties and sensitivity - the
same way it determines the sensitivity of a
unidirectional microphone.
For various application purposes, measurement conditions and process requirements,
series 40 sensors are available with three
antenna forms as VEGAPULS 42,
VEGAPULS 44 and VEGAPULS 45.
VEGAPULS 42 sensors are characterised by
1
G 1
/2 A or 11/2" NPT thread as process fitting.
These sensors are equipped as standard
versions with a ø 40 mm horn as antenna.
VEGAPULS 44 sensors are characterised by
a DIN or ANSI flanges as process fitting. In
standard version they are manufactured with
DN 50, 80, 100 and 150 as well as with ANSI
2", 3", 4" and 6". The bigger flanges come
equipped with respectively larger antenna
horns (ø 48, 75 and 95 mm).
Generally: The bigger the antenna horn, the
better the focusing characteristics, and the
better the antenna gain. This ensures that
even a weak product echo can be detected
reliably as level echo.
VEGAPULS 45 sensors are characterised by
integrated measuring tube. The measuring
tube serves the radar signals as a
waveguide in which no emitted energy is lost.
The complete emitted energy is returned as
reflection energy. Due to this, also products
with very weak reflection characteristics,
such as light petrol, liquid gas with
of 1.4 … 2.0 can be reliably detected.
ε
values
r
Viscous or adhesive products cannot be
measured with VEGAPULS 45.
Horn antennas
Horn antennas focus the
radar signals very well.
Manufactured from 1.4435
(StSt) or Hastelloy C22, they
are very rugged, and both
physically and chemically
resistant. They are suitable
for pressures up to 40 bar
and for medium temperatures up to 150°C. The horn
VEGAPULS 42
diameters determine the
focusing of the radar signals. The antenna gain increases with increasing horn
diameter (40, 48, 75,
95 mm).
The antenna gain represents
the relation between
transmitted energy and
received echo energy.
VEGAPULS 44
12 VEGAPULS 42, 44 and 45 – VBUS
Types and versions
Pipe antennas
Pipe antennas composed of horn antenna
and standpipe or bypass tube
Horn antennas on a standpipe or bypass tube form a
complete antenna system in
conjunction with a measuring
pipe (which must not be
perfectly straight, but can
also have bends). For the
radar signals, the measuring
pipe acts as a conductor.
The running time of the radar
signal changes in the pipe
and depends on the pipe
diameter. The sensor must
be therefore informed about
the tube inner diameter so
that the running time can be
taken into account and
precise level signals are
delivered. Pipe antennas are
best suited for turbulent
applications and products
with very low dielectric constant.
The antennas are
characterised by a very high
antenna gain. As a result,
high reliability is achieved
even with products having
very poor reflection properties.
VEGAPULS 42
pipe antenna
composed of
horn antenna and
bypass tube
VEGAPULS 44
pipe antenna
composed of
horn antenna and
bypass tube
VEGAPULS 45
with thread, pipe
antenna integrated in the
sensor
VEGAPULS 45
with flange, pipe
antenna integrated in the
sensor
Pipe antenna integrated in the sensor
VEGAPULS 45 series originated as a further
development of VEGAPULS 42 and 44
sensors combined with a surge pipe or
bypass tube. This sensor is equipped with
an optimised measuring tube up to 4 m long
and enables high precision level
measurement also in products with very
small dielectric figures of ε
liquid gas).
VEGAPULS 42, 44 and 45 – VBUS 13
= 1,4 … 1,8 (e.g.
r
3 Mounting and installation
3.1 General installation instructions
Mounting and installation
Measuring range
The reference plane for the measuring range
of the sensors is the flange face or the seal
shoulder of the thread. For measurements in
Keep in mind that in measuring environments
where the medium can reach the sensor
flange, buildup can occur on the antenna and
can cause measurement errors.
surge or bypass pipes with VEGAPULS 45
the max. measuring distance depends on the
tube length.
Reference
plane
max. filling
Measuring range (operating range) and max. measuring distance
Note: Use of the sensors for applications with solids is limited.
full
empty
Meas. range
max. measuring distance 20 m (type 45: 4 m)
Note: The use of series 40 sensors for solids
is restricted.
max.
min.
Interfering reflections
Flat obstructions and struts cause large
interfering reflections. They reflect the radar
signal with high energy density.
Rounded profile interfering surfaces scatter
the radar signals in all directions and thus
cause interfering reflections of lower energy
density. Hence, they ar e less critical than
reflections from a flat surface.
If flat obstructions in the range of the radar
signals cannot be avoided, we recommend
diverting the interfering signals with a deflec-
tor. Through scattering, the interfering signals
will be low in amplitude and so diffuse that
they can be filtered out by the sensor.
max.
max.
min.
Rounded profiles diffuse radar signals
Profiles with flat surfaces cause stronger interfering
signals
A deflector causes signal scattering
14 VEGAPULS 42, 44 and 45 – VBUS
Mounting and installation
Emission cone and interfering reflections
The radar signals are focused by the antenna system. The signals leave the antenna
in a conical path similar to the beam pattern
of a spotlight. The form and intensity of the
emission cone depend on the antenna used.
Any object in this beam cone causes a reflection of the radar signals. Within the first few
meters of the beam cone, tubes, struts or
other installations can interfere with the measurement. At a distance of 6 m, the false echo
of a strut has an amplitude nine times greater
than at a distance of 18 m.
At greater distances, the energy of the radar
signal distributes itself over a larger area,
thus causing weaker echoes from obstructing surfaces. The interfering signals are
therefore less critical than those at close
range.
If possible, orient the sensor axis perpendicularly to the product surface and avoid
vessel installations within the 100 % area of
the emission cone, e.g. tubes or struts.
The illustrations of the emission cones are
simplified and represent only the main beam
- a number of weaker beams also exist. Under difficult measuring conditions, the alignment of the antenna must be such that the
lowest possible false echo values appear.
Only giving attention to the size of the useful
echo is not always adequate when measuring conditions are unfavourable.
Optimum measuring conditions exist when
the emission cone reaches the measured
product perpendicularly and when the emission cone is free of obstructions.
0 m
Meas.
distance
10 m
Emission cone of a VEGAPULS 42 with screw-on
antenna and with ø 40 mm horn
Meas.
distance
3,50 1,90 3,501,900
0 m
VEGAPULS 42
22˚
30˚
50%
18˚
25˚
25%
VEGAPULS 44 with
ø 48 mm horn
m
In a difficult measurement environment,
searching for a mounting location with the
lowest possible false echo intensity will bring
the best results. In most cases, the useful
echo will then be present with sufficient
strength. With the adjustment software VVO
25%
on the PC, you can have a look at the echo
image and optimise the mounting location
(see chapter "5.2 Adjustment with the PC –
Sensor optimisation – Echo curve").
If possible, provide a "clear view" to the prod-
15 m
4,0 2,3 4,02,30
Emission cone of a DN 50 flange antenna
50%
m
uct inside the emission cone and avoid vessel installations in the first third of the
emission cone.
VEGAPULS 42, 44 and 45 – VBUS 15
Mounting and installation
0 m
Meas. distance
20 m
3,0 1,7 3,01,70m
VEGAPULS 44 with
ø 75 mm horn
10˚
20˚
50%
Emission cone of a DN 80 flange antenna
0 m
VEGAPULS 44 with
ø 95 mm horn
25%
3.2 Measurement of liquids
Flange antennas
In most cases, the mounting of radar sensors
is done on short DIN socket pieces. The
lower side of the instrument flange is the
reference plane for the measuring range. The
antenna must always protrude out of the
flange tube.
When the DIN socket piece is longer, please
make sure that the horn antenna is not cov-
ered completely by the socket. It is better if
the antenna protrudes slightly out of the
socket.
Reference plane
< 135 mm (DN 50)
< 210 mm (DN 80)
< 310 mm (DN 100, DN 150)
Mounting on DIN socket piece
When mounting on dished vessel tops, the
antenna length should at least correspond to
the length of the longer sockets.
Vessel center or
symmetry axis
Meas. distance
8˚
14˚
25%
<135…310mm
(250…425mm
with antenna
extension)
Mounting on a dished vessel top; max. socket length
20 m
2,5 1,3 2,51,30
50%
m
depending on flange size and, if applicable, on the
length of the antenna extension (see "7.3 Dimensions").
Emission cone of a DN 100 and DN 150 flange antenna
16 VEGAPULS 42, 44 and 45 – VBUS
Mounting and installation
On dished tank ends, please do not mount
the instrument in the centre or close to the
vessel wall, but approx.
1
/2 vessel radius from
the centre or from the vessel wall.
Dished tank ends can act as paraboloidal
reflectors. If the radar sensor is placed in the
focal point of the parabolic tank, the radar
sensor receives amplified false echoes. The
radar sensor should be mounted outside the
focal point. Parabolically amplified echoes
can be thereby avoided.
Vessel center or
symmetry axis
Reference plane
½ vessel radius
Mounting on dished tank ends
If the stability of the vessel will allow it (sensor
weight), flat mounting directly on the vessel
top is a good and economical solution. The
top side of the vessel is the reference plane.
Screw-on antenna
The screw-on antenna is mainly used on
small vessels. The antenna fits on small vessel openings down to 1
must not be longer than 135 mm (when using
the longer antenna, not longer than 250 mm).
Screw-on antenna on socket piece 11/2"
Screw-on antenna with antenna extension on socket
piece 1½"
1
/2" socket. The socket
Reference plane
≤ 135 mm
≤ 250 mm
As an alternative to socket mounting, the
screw-on antenna can be screwed into the
Reference plane
Mounting directly on the flat vessel top
VEGAPULS 42, 44 and 45 – VBUS 17
hole in the vessel.
Rod antenna directly on vessel opening
Mounting and installation
3.3 Measurement in standpipe
(surge or bypass tube)
General instructions
Pipe antennas are preferred in vessels which
contain many installations, e.g. heating tubes,
heat exchangers or fast-running stirrers.
Measurement is then possible where the
product surface is very turbulent, and vessel
installations cannot cause false echoes.
Through the focusing of the radar signals
within the measuring tube, even products
with low dielectric constant (ε
be measured reliably in the surge or bypass
tube. Note the following instructions.
Surge pipe welded
to the tank
Type label
= 1.6 to 3) can
r
Surge pipe in the
socket piece
maxmax
Make sure the required upper vent hole in
the surge pipe is aligned with the sensor
type label.
As an alternative to a surge pipe in the ves-
sel, a pipe antenna system outside the ves-
sel in a bypass tube is also possible.
The surge and bypass tubes must generally
be made of metal. For plastic tubes, a
closed, conductive jacket is always required.
For metal tubes with plastic inner coating,
make sure that the thickness of the coating is
minimal (approx. 2 … 4 mm).
Align the sensor such that the type label lies
on one axis with the tube holes or the tube
connection openings. The polarisation of the
radar signal enables a considerably more
stable measurement with this alignment.
Type label
> 300 mm
100 %
Vent hole
ø 5 … 10 mm
0 %
Tube flange system as bypass tube
When mounting a VEGAPULS 42 or 44 sen-
sor on a bypass tube (e.g. on a previous
min
without deflector
Pipe antenna systems in the tank
with deflector
min
floating or displacer unit), the radar sensor
should be mounted at a distance of approx.
300 mm or more from the max. level.
The surge or bypass tubes open at the bottom should reach to the requested min. level,
since a reliable measurement is only possible
within the pipe. The tube inner diameter
should be max. 100 mm and correspond with
the size of the antenna horn.
18 VEGAPULS 42, 44 and 45 – VBUS
Mounting and installation
> 300 mm
100 %
75 %
0 %
Extended bypass tube on a vessel with intense
product movements
For products with small dielectric constants
(< 4), a bypass tube longer than that required by the lower tube connection should
be used. Products with small dielectric constants are partly penetrated by the radar
signals, so that the tube bottom delivers a
stronger echo than the product (when the
bypass tube is nearly empty). As a result of
the extension of the lower tube end, sufficient
liquid will remain even when the vessel is
emptied.
With a liquid quantity of 300 … 800 mm in the
blind lower end of the tube, the portion of the
signal that penetrates the liquid and reflects
from the tube bottom is sufficiently damped the sensor can then easily distinguish it from
the echo of the liquid surface. If not enough
liquid remains, a deflection plate located at
the bottom of a vertical pipe can provide the
same function. It deflects the signal reflected
from the tube end sideways into the standard
tube opening.
Connections to the bypass tube
The connections to the bypass tubes must
be fashioned in such a way that only minimal
reflections are caused by the walls of the
connecting tubes. This is especially important
for the breather connection in the upper part
of the tube. Observe the following points:
• Use small openings for the connection.
• The diameter of the connecting tubes
should not exceed 1/3 of the bypass diameter.
• The tube connections must not protrude
into the bypass.
• Large welding beads in the tubes should
be avoided.
• Additional connections to the bypass tube
are more suitable if they lie on the same
plane as the upper and lower vessel connection (superimposed or displaced by
180°).
Type label
> 300 mm
100 %
Optimum connection to the bypass tube
0 %
Bypass tube with tube stub
VEGAPULS 42, 44 and 45 – VBUS 19
300 ... 800 mm
Welding beads too large
Tube connection protrudes
Mounting and installation
Conducting tube
Conducting tube in existing surge or bypass tube
To increase the min. distance, the conducting
tube can protrude out of the surge or bypass
tube. For this purpose, a plain flange can be
welded at the required position on the outside of the extended conducting tube. In
both cases, an adequate vent hole must be
provided.
Additional connection to the bypass tube in one plane
Use of conducting tubes
(VEGAPULS 44)
In case of very rough inner surfaces in existing bypass tubes (e.g. due to corrosion) or
in case of big connection openings as well as
bypass tubes with an inner diameter of more
than 100 mm, the use of a conducting tube in
the existing bypass tube is recommended.
This reduces the noise level and increases
reliability considerably. The flange of the
conducting tube can be easily mounted as a
sandwich flange between vessel and sensor
flange.
20 VEGAPULS 42, 44 and 45 – VBUS
Extended conducting tube
Mounting and installation
Seals on tube connections and tube extensions
Microwaves are very sensitive to gaps in
flange connections. If connections are made
without proper care, distinct false echoes as
well as increased signal noise can result.
Observe the following points:
• The seal used should correspond to the
tube inner diameter.
• If possible, conductive seals such as conductive PTFE or graphite should be used,
especially for thicker seals.
• Make sure that there are only a few seal
positions on a conducting tube.
Flange connections on bypass tubes
Adhesive products
For slightly adhesive products, choose a
surge pipe with e.g. a nominal width of
50 mm. VEGAPULS 42 and 44 radar sensors
with 26 GHz technology are relatively insensitive to buildup in the tube. Nevertheless,
buildup must not be allowed to plug up the
tube completely.
For adhesive products, the use of a DN 80 to
max. DN 100 stand/surge pipe can enable
measurement in spite of buildup. Products
that cause excessive buildup cannot be
measured in a standpipe.
VEGAPULS 45 with integrated measuring tube
The sensor version VEGAPULS 45 is especially developed for measuring tube applications and is supplied complete with a 27 mm
measuring tube. With a measuring tube
length up to 4 m, this sensor version is suitable e.g. for the use in existing standpipes.
max
min
VEGAPULS 45 with integrated measuring tube in a
free vessel or in an existing bypass pipe
Note:
VEGAPULS 45 sensors with integrated
measuring tube are equipped with a
threaded process fitting or a flange connection. For sensors with threaded process
fitting, make sure that the complete sensor,
i.e. also the sensor housing, turns when
screwing in. The sensor housing is fastened
with a clipped connection. This sensor housing must not be turned with respect to the
measuring tube or even loosened. Otherwise
the radar signal coupling would be
destroyed and the sensor would not function
proberly.
VEGAPULS 42, 44 and 45 – VBUS 21
Mounting and installation
If you want to measure inhomogeneous products or stratified products in a surge pipe, it
must have holes, elongated holes or slots.
These openings ensure that the liquid is
mixed and corresponds to the liquid in the
vessel.
The more inhomogeneous the measured
product, the closer the openings should be
spaced.
Due to radar signal polarisation, the holes or
slots must be positioned in two rows offset
by 180°. The radar sensor must then be
mounted so that the type label of the sensor
is aligned with the rows of holes.
VEGAPULS 45 with integrated measuring tube (surge
pipe) measures between the heating spirals
Standpipe measurement of inhomogeneous products
ø 5...15
homogeneous
liquids
slightly inhomogeneous
liquids
ø 5...15
Every wider slot causes a false echo. The
slots should therefore not exceed a width of
10 mm, to keep the signal-to-noise ratio at a
minimum. Round slot ends are better than
rectangular ones.
Type label
ø 5...15
VEGAPULS 44: Rows of holes on one axis with the
type label
inhomogeneous liquids
Openings in a surge pipe for mixing of inhomogeneous products
22 VEGAPULS 42, 44 and 45 – VBUS
Mounting and installation
Surge pipe with ball valve
If a ball valve is mounted in the surge pipe,
maintenance and servicing can be carried
out without opening the vessel (e.g. if it contains liquid gas or toxic products).
Ball valve
ø50
Tube antenna system with ball valve cutoff in measuring tube
A prerequisite for trouble-free operation is a
ball valve throat that corresponds to the pipe
diameter and provides a flush surface with
the pipe inner wall. The valve must not have
any rough edges or constrictions in its channel and should have a min. distance of 300
mm from the sensor flange.
> 300 mm
Vent hole
Deflector
Guidelines for standpipe construction
Radar sensors for measurement on surge or
bypass pipes are used with G 1½ A
screwed-on antenna or flange sizes DN 50,
DN 80, DN 100 and DN 150. The radar
sensor with a DN 50 flange is only a
functional measuring system in conjunction
with a measuring tube.
On the left you see the constructional features of a measuring pipe (surge or bypass
tube) as exemplified by a sensor with DN 50
flange.
The measuring pipe must be smooth inside
(average surface quality Rz ≤ 30). Use stain-
less steel tubing (drawn or welded lengthwise) for construction of the measuring pipe.
Extend the measuring pipe to the required
length with welding neck flanges or with connecting sleeves. Make sure that no shoulders
or projections are created during welding.
Before welding, join pipe and flange with their
inner surfaces flush and exactly fitting.
Avoid welding through the pipe wall. The pipe
must remain smooth inside. Roughness or
welding beads on the inner surfaces must be
carefully removed and burnished, as they
cause false echoes and encourage product
adhesion.
On the following page you will see the
constructional features of a measuring pipe
as exemplified by a sensor with DN 100
flange.
If the vessel contains agitated products,
fasten the measuring pipe to the vessel bottom. Provide additional fastenings for longer
measuring pipes.
VEGAPULS 42, 44 and 45 – VBUS 23
Mounting and installation
0 %
Flange
DN 100
Deburr the
holes
150…500
Connecting
sleeve
Welding neck
flanges
VEGAPULS 44
When measuring products with lower dielectric values (< 4), a part of the radar signal
penetrates the medium. If the vessel is nearly
empty, an echo is generated by the medium
and the vessel bottom. In some cases, the
vessel bottom generates a stronger signal
echo than the product surface. With a deflector on the measuring pipe end, the radar
signals are scattered. In nearly empty vessels and products with low dielectric value,
the medium then generates a stronger echo
than the vessel bottom.
Thanks to the deflector, only the useful signal
is received in a nearly empty vessel - the
Welding of the plain
welded flange
100 %
ø 95
2
Welding of the connecting sleeves
5…10
correct measured value is thus transmitted
and the 0 % level reliably detected.
Instead of a deflector, the standpipe or surge
pipe can be equipped with a quadrant pipe
at the end. This reflects the radar signals that
penetrate the medium diffusely to the side
and reduces strong echoes from the tube
0,0…0,4
3,6
Welding of the welding
neck flange
3,6
1,5…2
0,0…0,4
end or vessel bottom.
0 %
Quadrant pipe on the bypass tube end
Deflector
0 %
ø 100,8
~45˚
Meas. pipe fastening
Vessel
bottom
Quadrant pipe on the standpipe end
24 VEGAPULS 42, 44 and 45 – VBUS
Mounting and installation
3.4 False echoes
The mounting location of the radar sensor
must be selected such that no installations or
inflowing material cross the radar impulses.
The following examples and instructions
show the most frequent measuring problems
and how to avoid them.
Vessel protrusions
Vessel forms with flat protrusions can, due to
their strong false echoes, greatly effect the
measurement. Shields above these flat protrusions scatter the false echoes and guarantee a reliable measurement.
Correct Wrong
Vessel protrusions (slope)
Intake pipes, i.e. for the mixing of materials with a flat surface directed towards the sensor - should be covered with a sloping shield
that will scatter false echoes.
Vessel installations
Vessel installations such as, for example, a
ladder, often cause false echoes. Make sure
when planning your measuring location that
the radar signals have free access to the
measured product.
Correct Wrong
Ladder
Vessel installations
Ladder
Struts
Struts, like other vessel installations, can
cause strong false echoes superimposed on
the useful echoes. Small shields effectively
hinder a direct false echo reflection. These
false echoes are scattered and diffused in
the area and are then filtered out as "echo
noise" by the measuring electronics.
Correct Wrong
Correct Wrong
Struts
Vessel protrusions (intake pipe)
VEGAPULS 42, 44 and 45 – VBUS 25
Shields
Mounting and installation
Inflowing material
Do not mount the instrument in or above the
filling stream. Ensure that you detect the
product surface and not the inflowing material.
Correct
Inflowing material
Wrong
Buildup
If the sensor is mounted too close to the
vessel wall, buildup and adhesions of the
measured product to the vessel wall will
cause false echoes. Position the sensor at a
sufficient distance from the vessel wall.
Please also note chapter "3.1 General installation instructions".
Correct Wrong
Strong product movements
Strong turbulences in the vessel, e.g. caused
by stirrers or strong chemical reactions, can
seriously interfere with the measurement. A
surge or bypass tube (figure) allows, provided the product causes no buildup in the
tube, a reliable measurement even with
turbulences in the vessel.
Correct Wrong
100 %
75 %
0 %
Strong product movements
Buildup
26 VEGAPULS 42, 44 and 45 – VBUS
Mounting and installation
3.5 Installation mistakes
Socket piece too long
If the sensor is mounted in a socket extension that is too long, false reflections are
caused and measurement is hindered. Make
sure that the horn antenna protrudes out of
the socket piece.
Correct Unfavourable
Reference
plane
Flange antenna: Correct and unfavourable socket
length
Unfavourable
Correct
Parabolic effects on dished or arched
vessel tops
Round or parabolic tank tops act like a parabolic mirror on the radar signals. If the radar
sensor is placed at the focal point of such a
parabolic tank top, the sensor receives amplified false echoes. The optimum mounting
position is generally in the range of half the
vessel radius from the centre.
Correct
~ ½
vessel
radius
Unfavourable
Unfavourable
< 135 mm
(250 mm)
Screw-on antenna: Correct and unfavourable socket
length
VEGAPULS 42, 44 and 45 – VBUS 27
Mounting on a vessel with parabolic tank top
Mounting and installation
Wrong orientation to the product
Weak measuring signals are caused if the
sensor is not directly pointed at the product
surface. Orient the sensor axis perpendicularly to the product surface to achieve reliable
measuring results.
Correct Wrong
Ladder
Direct sensor vertically to the product surface
Ladder
Sensor too close to the vessel wall
If the radar sensor is mounted too close to
the vessel wall, strong false echoes can be
caused. Buildup, rivets, screws or weld joints
superimpose their echoes onto the product
or useful echo. Please ensure sufficient distance from the sensor to the vessel wall.
Foam generation
Conductive foam is penetrated by the radar
signals to different depths and generates a
number of single (bubble) echoes. The signals in the foam are also damped, like heat
radiation that tries to penetrate styrofoam.
Thick, dense, creamy foam, and especially
conductive foam, on the product surface can
cause incorrect measurements.
conductive
foam
Liquid
In case of good reflection conditions (liquids
Foam generation
without vessel installations), we recommend
selecting the sensor distance so that there is
no vessel wall within the inner emission cone.
For products in less favourable reflection
environments, it is a good idea to also keep
the outer emission cone free of interfering
installations. Note chapter "3.1 General installation instructions".
Take measures to avoid foam, measure in a
bypass tube or use a different measuring
technology, e.g. capacitive electrodes or
hydrostatic pressure transmitters.
In many cases, VEGAPULS 54 radar sensors
with 5.8 GHz operating frequency achieve
considerably better and more reliable measuring results in foam applications than type
40 sensors with 26 GHz technology.
28 VEGAPULS 42, 44 and 45 – VBUS
Loading...