MALÅ CX12 Manual

MALÅ CX12 Manual
CX and HF antennas
Main unit for the MALÅ Geoscience
High frequency antenna series
Operating manual
Version 2.7
Table of Contents
Unpacking and Inspection
Repacking and Shipping
MALÅ Geoscience Indemnity Clause
Important information regarding the use of this MALÅ GPR unit 5
CX Start up
2D Project
3D/Grid Project
Creating a 3D/Grid Project
Migration settings and Images for 3D/Grid Projects
Object-Mapper Project
EM Option
Resulting signals/images
GPS Functionality
File Manager
Transferring data
System settings
Units screen
Wheel screen
GPS settings screen
Batteries and Power supply
High Frequency antennas
Technical Specifications CX unit
Technical specifications HF Antennas
1 Introduction
Thank you for purchasing the MALÅ CX, the main unit for operating the
MALÅ High Frequency antennas, both with and without EM option. CX10
gives you a High Brightness type of screen, while CX11 is equipped with a
Trans-reflective screen for best performance in bright daylight. The MALÅ
CX has built-in software for both data collection and on-site interpretation,
tailored for high-frequency applications, as concrete investigations.
We at MALÅ Geoscience welcome comments from you concerning your
experiences in using this equipment, as well as your impressions of this
manual. Please take the time to read through the assembly instructions
carefully and address any questions or suggestions to the following:
Main Office:
MALÅ Geoscience AB
Skolgatan 11
S-930 70 Malå
Phone: +46 953 345 50
+46 953 345 67
North & South America:
MALÅ Geoscience USA, Inc.
2040 Savage Rd, P.O. Box 80430
Charleston, SC 29416
Phone: +1 843 852 5021
Fax: +1 843 769 7392
MALÅ Geoscience
R.2604, Yuan Chen Xin BLDG
No. 12 Yu Min Rd, Chao Yang Distr.
Beijing 100029, China
Phone: +60 3 6250 7351
Fax: +60 3 6250 2072
Technical support issues can be sent to:
Information about the products from MALÅ Geoscience is also available on Internet:
1.1 Unpacking and Inspection
Great care should be taken when unpacking the equipment. Be sure to
check the contents against those shown on the packing list and inspect the
equipment for any loose parts or other damage. All packing material should
be preserved in the event of damage occurring during shipping. Any claims
for shipping damage should be filed with the carrier. Any claims for missing
equipment or parts should be filed with MALÅ Geoscience.
1.2 Repacking and Shipping
If the original packing materials are not available, the equipment should be
packed in at least 80 mm of absorbing material. Do not use shredded
fibers, paper wood, or wool, as these materials tend to get compacted
during shipping, thus permitting the instruments to move around inside the
1.3 MALÅ Geoscience Indemnity Clause
Operators of MALÅ CX or other MALÅ GPR systems shall hold harmless,
defend, and indemnify MALÅ Geoscience from and against any and all
losses, liabilities, damages, injuries, claims, demands, costs and expenses
or claims including claims by third parties arising out of the use or
possession of the MALÅ GPR system.
1.4 Important information regarding the use of this
According to the regulations stated in ETSI EN 302 066-1 (European
Telecommunication Standards Institute):
The CX unit should not be left ON when leaving the system
unintended. It should always be turned OFF when not in use.
The antennas should point towards the ground, walls etc. during
measurement and not towards the air.
The antennas should be kept in close proximity to the media under
See also Chapter 9 System Settings.
2 CX Start up
Before starting up the MALÅ CX GPR system the following connections
must be made:
The CX to the antenna, using the antenna cable. The antenna cable
should always be connected before the CX unit is powered on.
The CX to the battery or other power source, using the battery cable.
See Chapter 11.
The encoder wheel to the antenna.
When all connections have been made, the CX can be turned on. Pressing
the On/Off button at top right-hand corner activates the system. More
information on the High Frequency Antennas can be found in Chapter 12.
Note! The antennas should be ON for a while before measurement, to
warm-up. An appropriate time is approximately 10 minutes.
Once active, the CX is operated using a dual function turn-push button
(bottom right on the monitor) to control the settings. By turning the button
right or left, a selection from a specific menu can be highlighted. By
pushing the button, the selection is activated.
There is also possible for the operator to navigate and execute all functions
using the remote buttons on the antenna (Figure 12.5), the HF cart (Figure
12.2) and on the extension pole (Figure 12.6). By pressing either the black
or red button the operator moves in-between the individual menus on the
screen and activates the selection by pressing the two buttons at the same
The following screen is shown at start-up of the CX and the work flow of the
3 different project types are also shown below:
Main menu
2D Projects
Object Mapper Projects
3D Projects
General settings
General settings
General settings
3D settings
OM settings
Data collection
Data collection
Data collection
As seen three different measurement modes are available for the CX
system; 2D, 3D/Grid and Object-Mapper Projects. All these project types
are explained in detail in the following chapters.
However, for all of these three options, general measurements settings are
done first of all and in quite a similar way, so when selecting one of the
options (2D, 3D/Grid or Object-Mapper) the following screen is seen, the
General Settings window:
In this menu the options for changing Antenna, Material Type, Depth
Window, Zero Depth, Acquisition mode (Wheel / Time) and Point Interval
are found. If the Filters options in turned ON (done in the System Settings,
see Chapter 9) it also shows up here.
The trace and radargram view (right side of the screen) shows directly how
the signal looks like. Moving the antenna over a surface will change this
view of the wiggle trace and the gray scale background.
Using the turn-push button or the remote buttons, each setting to be
changed is chosen (high-lighted) and the button pressed to activate it.
Once this is done, the different options are displayed and can be changed
by turning and pushing the button. Examples are shown below for changing
the Antenna and Wheel options.
The Depth window (seen at right) defines depth of the measurement; in
other words the total length of time the electromagnetic wave is
transmitted. Three predefined depths are available, shallow, medium and
deep. Choose the appropriate one by pressing the turn-and-push knob or
use the remote buttons. Note! The depth window is depending on the
velocity of the material.
The option Find zero depth
is used to define the surface
level of the measurements.
To do this, activate the option
and follow the instructions on
the screen. The antenna is
hold on the ground in the
same position as where you
will measure.
The Material type is chosen
accordingly to the medium the GPR
investigation is carried out in. The
CX system lists a number of different
types of material and is a guide for
the operator when estimating the
depth to targets visible in the
It is important to choose the material type and by that velocity carefully as
this affects the velocity (the velocity of the electromagnetic radar wave),
which is used to calculate the depth of the measurement.
When the correct material type is
selected, the velocity can be
changed according to the limits, or
estimated with the Velocity Wizard.
It should be remembered that the
velocity of electromagnetic waves is
lower in wet materials than in dry.
After the material velocity has been selected, two buttons will appear on the
screen, OK to confirm and go back General Settings and Cancel to do a
new selection.
After selection of material type or by choosing User-defined the option
Velocity Wizard can also be entered to obtain correct velocity for the
media. The requirement to use the Velocity Wizard (both for the migration
and hyperbola fitting function) is that a point object needs to be visible in
the radargram.
Note! When using a hyperbola the best estimation of the velocity is made
when the linear object is passed in 90 degrees.
When choosing the Velocity Wizard
the following screens are seen, giving
you the option to carry out a short
measurement, find an object and by
that a hyperbola, to migrate or use for
hyperbola fitting as tools to estimate
the velocity.
Press Start to start the measurement.
Using the Migration option
Migration is a tool used to get an accurate picture of the subsurface. It
involves repositioning of return signals to show where structures are
located rather than where signals was picked up.
Change the Velocity until the best migrated picture is obtained.
Migration ON
Migration OFF
Using the Hyperbola fitting
The theoretical hyperbola is moved over the screen by activating the X-pos and
Y-pos buttons and the angle of the legs are adjusted to the hyperbola on the
radargram screen by changing the Velocity.
Note! If you select a velocity value outside selected materials range, the
material will be set to “User-Defined”
The option Acquisition mode (in the General Setting view) and Wheel is
changed depending on how the measurements are to be gathered; by time
or by distance. If distance is chosen the correct encoder is selected. The
standard MALÅ Geoscience wheels are found in the list.
Point interval (or time in seconds) gives the distance between the
measured traces in the radargram.
Note! For 3D/Grid and Object-Mapper projects only the wheel acquisition
mode is available. Point interval is fixed in 3D/Grid projects depending on
the used antenna.
For all project types (2D, 3D/Grid and Object-Mapper) the filename is given
automatically by the CX system. See also Chapter 8 File Manager.
Note! To turn off the unit once the work is completed, use the QUIT-button
and then the on/off switch on the unit. If the unit is switched off using only
on/off switch, the file system in the unit can be corrupted and all the data
After using the QUIT option in the program and the power has been turned
off by the software, the user need to power off the CX unit by pressing the
ON/OFF switch on the unit itself. To turn the unit on again, wait for 5-10
seconds before pressing the ON/OFF switch.
3 2D Project
2D Projects are defined as measurement in single profiles as seen below:
Concrete bottom
This type of project can for instance be used to the investigate layer
thicknesses, as concrete floors, asphalt thicknesses on roads, ice thickness
When the measurement settings (in the General Settings window) are done
is pressed the following screen is seen:
Radargram screen (the resulting picture)
Main menus.
Battery Status Indicator
Information Line showing the material type, the connected antenna
type, measurement depth, memory space and acquisition mode.
By choosing Start pressing the
turn-push button, a radar
profile measurement can be
started immediately.
By pressing
operator has the possibility to
save a screenshot image of
the radargram seen on the
Note! See Chapter 7 for
measurements with a GPS.
As each profile is completed, press STOP to finish the project. The data
can be moved from the CX to a PC for further interpretation work (see the
Section Transferring data). Files can be continued by pressing NewP (New
Profile). To start a new 2D project press Exit and then start from the main
menu again.
To improve the visualization of radar data on the screen the CX provides
the operator with different filter and contrast options. For each option the
turn-push button is rotated to increase or decrease the effect.
Applies a background removal filter.
Changes the contrast of the radargram.
Applies time gain on the measured traces. The
settings for this filter can be changed, see
System Settings, Chapter 9.
A FIR filter can also be applied on the data, see Chapter 9.
Also in the 2D measurement mode, migration is possible, when the profile
is stopped.
4 3D/Grid Project
3D/Grid Project is a tool that makes the gathering and visualization of radar
data measured in two perpendicular directions easier, directly in the CX
unit. A typical application for which 3D/Grid Projects are effective is the
mapping of re-bars and joists in concrete. The 3D/Grid Project option in the
CX will guide you through all steps involved in the data collection to the
final processed 2.5D view of the investigated area. The measurement can
be carried out using a grid-mat, for fast and easy data collection (Fig 3.1).
Figure 3.1
Examples of 3D/Grid Project measurements with a grid-mat.
For best result the grid-mat and the investigation lines should be placed as
perpendicular to the searched object as possible. If no knowledge of the
direction of for instance a rebar net is available, it is advisable to carry out
some test measurements prior the 3D/Grid Project. This can be done by 23 single parallel profiles giving an indication of how the objects are situated.
See Fig. 3.2.
Figure 3.2
Three single profiles are measured, and indications of
objects are marked with red. The 3D/Grid Project is carried out with one
direction along the interesting objects and one direction perpendicular to
the objects.
4.1 Creating a 3D/Grid Project
When the option 3D/Grid Project is chose and the measurements settings
are made (Note! Point interval is fixed in 3D/Grid projects depending on the
used antenna), press
to reach the 3D/Grid Project window.
The CX system automatically will give the project a name.
Here the parameters for the
grid is set, in terms of size and
lines spacing of the wanted 3D
If pressing Use Standard
Carpet the size will be set to
0.80 x 0.8 m and 0.10 cm line
spacing as the size of the
standard MALÅ Geoscience
Note! The Grid size should be evenly divisible by the Line spacing. This is
applied automatically by the CX system. In other words, if you change the
line spacing, the grid size will also change to become the nearest divisible
value. The same applies the values of Grid size.
Press continue to reach the 3D/Grid Grid project layout screen to do a final
check of the project parameters:
Choosing Start activates the 3D/Grid Project. During data collection the two
buttons on the antenna or on the extension handle are used as remote
controls, for choosing the Next profile and Start profile.
The number in the blue rectangle
refers to the distance on the grid
Place the antenna carefully over the
start position (the red triangle shows
the start point and direction), then
follow the step below:
1) Press the black button, wait for a beep, and release the black
2) Start to measure, by moving the antenna along the line on the
3) Continue the measurement until a beep is heard again. The CX
automatically ends the line.
4) Press the red button (to change measurement line), and wait for a
5) Place the antenna in the start position of the next line and start
from step 1 again.
If black button is pressed after a profile is collected, the software assumes
that the operator want to re-measure the current profile. The option
can also be chosen to re-measure the previous lines.
When all lines in one direction are
automatically will change to the
second direction.
Once the last profile is filled, press the red button one more time, then
press the “Process“ button, to process and view the data. This will take
some minutes.
This screen (above on right) shows the result of the calculations made to
create vertical and horizontal slices of the measured volume. The vertical
slice is seen on the right (X- or Y- direction) and the Top View, the
horizontal slice, is seen on the left.
By choosing one of the sections and turning the turn-push button the
sections can be scrolled to look at data within the cube, from the sides or
the top.
For explanation of the three function buttons:
section in this manual.
see next
The options Angle, Aperture and Threshold are filter settings for the Top
View and stands for:
Angle – The space between the single lines of data is being filled with
the help of an interpolation scheme. This interpolation can be
performed in different directions the angle parameter determines this
direction, -45 – +45. A value of 0 indicates orthogonal interpolation, the
normal case. This filter should mainly be used when the target
directions are not parallel with any of the profile sets.
Aperture – When targets are not exactly horizontal, it helps a lot if one
can view a depth/time interval instead of an instant time slice. This
parameter determines the thickness of the merged time slices. It should
be altered in order to better follow a dipping target or to view several
targets, on different depths, in the same top view. When the parameter
is altered, the time/depth span is shown interactively on the side view.
Threshold – This is a composed filter. It mainly sets a threshold on the
top view data. If we go to the positive direction then levels below the
threshold is given some fixed negative value and levels above are
presented. If we go to the negative direction then levels above the
threshold is given some fixed positive value and levels below are
presented. The parameter is expressed in percent of maximum or
minimum amplitudes found the dataset.
one can toggle to a full screen of the Top View.
When pressing
Here there is a possibility to save an image of the selected view as a result
of the investigation. These images will be saved with an automatic name.
The image format is chosen in the System setting, Chapter 9.
A circle can be turned ON and OFF and moved in the picture, as a guide to
detected objects or to mark areas with no objects. The diameter of the
circle can also be change in size by changing the D value.
Saved screenshot
The measured projects and created images can of course also be
uploaded to a computer (see the section on Transferring Data).
4.2 Migration settings and Images for 3D/Grid
When the 3D/Grid project is ready, there are a number of different options
available on the screen, in addition to the filter settings explained above.
By pressing
, the user
can view the settings of the
By pressing the
it is possible to change the
Velocity settings (Migration)
or to create Image Slices.
Note! Make sure that a welldefined hyperbola is visible
in the right hand screen
before entering the Velocity
Settings (Migration window).
Migration is a processing scheme which can significantly sharpen the
radar image, especially when seen in the top view. Using this option, an
appropriate velocity for the migration can be selected, by changing
is also a background removal filter for 3D/Grid project.
With the Image Slice Generator
images can be generated in freely
set depth ranges. See example
The distance is given as the distance between the individual slices
created within the depth range.
The pictures are saved in an own catalogue, named as:
ProjectName_S0001, where 0001 will be a unique sequence number.
Example of how images can be saved.
5 Object-Mapper Project
An Object-Mapper Project is a tool to easily handle and interpret radar
profiles acquired with the MALÅ CX system, where a number of radar
profiles are measured parallel starting from a common baseline. See the
example below.
Applications can be for instance; mapping pipes, conduits or other larger
linear structures, over larger areas.
Linear structure
CX Profiles
Once an Object-Mapper Project is created within the MALÅ CX, it can be
directly opened in Object Mapper, a Windows based interpretation software
for quick mapping of underground features. For further information, see the
Object Mapper Operating Manual.
When the Measurement settings are made, (see Chapter 2 above) press
and choose the appropriate settings for the Object-Mapper
Give the distance between the profiles, decide direction and line spacing.
The direction right and left is defined as shown below:
2nd 1st
1st 2nd
Profiles are made on the right-hand
side of the 1 profile
Profiles are made on the left-hand
side of the 1 profile
Note! In an Object-Mapper project the measurement lines are measured
parallel to each other and orthogonal to the baseline.
Press Start to measure the first line, press Stop when finishing it and
in the same way until all profiles are collected, and then
press Exit.
6 EM Option
The MALÅ High Frequency antennas are also available with an EM option.
These antennas are equipped with 50/60Hz electromagnetic (EM) sensors,
to provide the CX with a combination of the radar and EM technologies to
better locate and identify energized power cables, rebar, post-tension
cables plus metallic and non-metallic conduits in concrete slabs either
suspended or on grade.
When an antenna with the
EM option is available and
running it is seen in the
General Settings Window.
When measuring, the CX
works as an ordinary CX unit
also with the EM High
results of the EM measurements will be seen at the
bottom of the radargram
screen when a new profile is
The EM option is of course
also active when measuring
displayed as a Top view,
on the 3D/Grid Project 2,5D
View screen when selecting
the option EM Data.
The EM-option is mainly designed for detection of the leakage from AC
power lines. This leakage is highly dependent on how the cable is designed
i.e. a cylindrical twisted cable will have much less leakage than the cables
commonly put into plastic pipes in walls.
The leakage from power lines will result in a leakage field, which is
dependent on the distance between the “hot” cable and the return line as
well as of the current flowing in the lines and the distance from the coil to
the cable. On top of this the measured field is also dependent on the
location of the two lines with respect to the coils in the antenna.
The EM sensor system built into the antenna measures the vertical
amplitude of the leaked magnetic field from the cable.
There are EM-sensors on each side of the antenna and they detect the
magnetic field independently. The results from the left hand sensors are
presented as a red line and the right hand as a green line, see picture
In the 2D operation mode the resulting two signals are plotted, using a
logarithmic scale. When used in the Grid project mode, the two signals are
averaged and plotted in a separate top view.
6.1 Resulting signals/images
The exact shape of the EM signal is difficult to predict since the number of
possible source geometries is so large. In general, though, the maximum
variation in the EM signal occurs around the cable. For a flat horizontal twowire cable, e.g. the signal has an almost anti-symmetric shape with a
positive peak on one side of the cable and a negative peak on the other.
These peaks are generally not symmetrically located and their height will
be different. For other cable geometries there may be only one peak over
the cable.
When the cable is twisted the EM signal can vary very rapidly over short
distances, making precise location of the cable more difficult.
In the 3D/Grid Project view the average signal at each point of
measurement is plotted along each survey line and then interpolated over
the surface. The location of any cable will be highlighted by areas of larger
EM variation. In the case of a flat cable, the line separating the two shades
is pinpointing the cable. See example above where the mapped cable was
situated 2-3 cm below the floor surface. And again, in the case of a twisted
cable, the image might become blurred.
6.2 Sensitivity
The EM sensor system was designed with a detection limit equal to the
leakage from a cable carrying 260mA at 10cm distance, e.g. 60W in a
230V system. Higher current might of course enable larger detection
The EM sensors primarily detect current carrying cables, but in a noisy
environment, all metal structures might carry 50/60 Hz by induction.
As mentioned before the EM-sensors are designed to identify an electromagnetic leakage. This leakage will be dependent on how well the cable is
balanced. A cylindrical twisted cable will be harder to detect than a flat pair.
In walls cabling is usually made up of individual cables inside plastic pipes.
These are rather easy to detect. Be aware of the fact that electrical engines
as well as transformers can produce strong fields, disturbing the sensors.
7 GPS Functionality
The CX system is available with a positioning system, GPS, which can be
used with 2D and Object Mapper measurements. To activate this
functionality an activation code is needed (contact your local sales
representative for more information). The GPS is connected to the CX main
unit via the USB port. When a GPS is connected the system immediately
start to log the positioning data with x, y and z-coordinates. The coordinates
are saved in a file (*.cor) and can be transferred to a PC according to
Chapter 8 File Manager.
The status of the GPS is shown in the Main menu, as follows:
Gray: GPS functionality enabled, but no
GPS-device is connected.
Red: GPS functionality enabled, GPSdevice connected but no position can be
received by the GPS-device.
Green: GPS functionality enabled, and
positioning information is received from the
The MALÅ GPS standard, GPS format contains the following information:
trace number, date, latitude, longitude, height above mean sea level, and
HDOP. The HDOP value is a theoretical measure of the accuracy in the
horizontal coordinates based on the positions of the available GPS
satellites. A lower value indicates better accuracy. The date and time is
expressed in Greenwich Time zone. An excerpt from a data file is seen
Trace date
1 2008-05-14 08:52:44
2 2008-05-14 08:52:49
16 2008-05-14 08:52:51
latitude N
longitude E “height above MSL” M
59.368000 N
59.368000 N
59.368008 N
18.248722 E
18.248722 E
18.248701 E
15.9 M
15.4 M
15.1 M
The GPS system functioning with the CX system is: GPS receiver
GLOBALSAT BU-353 (30-002002A)
The USB port is found top left on the CX Main unit, under the cap.
Note! The GPS should not be connected to the main unit before the CX
system is powered and running.
8 File Manager
As a profile measurement is started (2D Project) the data is automatically
saved and named as in the following files:
2D_0001.rd3 - data (traces)
2D _0001.rad - header (measurement info)
2D_0001.cor – coordinates if a GPS I connected to the system
2D _0001.em - EM data (if using antennas with EM option)
During a 3D/Grid Project the following data file is created:
3D_0001.rhd - a file directory containing all files measured (in two
directions _1 and _2, in the 3D/Grid Project called 1. File extension
follows the above mentioned; however EM data files are named
3D_001_1.emm or _2). Deleting/moving a 3D/Grid project removes
all files belonging to the project.
3D_001_S0001 – a file directory containing images slices.
The Object-Mapper Projects will result in the following files:
OBM_0001.obm - a file directory containing all files measured.
Deleting/moving an Object-Mapper project removes all files
belonging to the project.
OBM_0001_P01.rd3 and .rad – the single files in the OBM_0001
Other files:
(Project name)_0001.jpeg or png, bmp, tga and tif – an image file of
a selected view. If several images are saved the file names will be
G001_002 and so on. G001 refers to the Grid Project they belong to.
Every file belonging to a
specific measurement has
the same file name, and
the file extension specifies
the type of data in the file.
The previously measured
files can be viewed within
the CX by pressing Work
with Files in the main
Under this menu, the operator can choose to view files, delete them or
upload those (See Section Transferring Data). To select a file turn the turnpush button to the file name and press to select.
To mark and select several
files at the same time, use
the Mark option.
Now the operator can
choose to open them,
delete them or upload them
to a PC.
Some settings can also be changed when a profile is opened. These are
the settings concerning Color and Soil Velocity. The filters, contrast and
time gain function are also applicable to viewed radargrams.
When viewing radargrams the operator can select and press the horizontal
scrolling. When the scroll bar is selected it turns blue and scrolling through
the data is carried out by turning the button. If the file is very large the
operator can press the turn-push button and rotate it without releasing it so
the profile is scrolled very fast horizontally and redrawn after the release of
the button.
8.1 Transferring data
By connecting a flashcard (USB storage media) to the USB port at the top
left corner of the CX the measured data can be easily transferred by
in the File dialog (See the section File Manager). All
marked files and grid projects will then be copied to the storage medium,
which can then be connected to any desired computer.
The USB port is found top left, under the black cap.
9 System settings
The System menu of the CX unit can be
reached after choosing Quit on the main
menu, as if to shut down the unit. It is
reached by turning the turn-push button
3 clicks right, 3 clicks left and 3 clicks
right at the following screen.
In the System Menu the following changes are possible:
- Time and date
- Battery installation to set battery indicator level
- Activate the kill-switch. See below.
- Missed traces. If measurements are carried out too fast, this mode
guarantees that the traces are placed in correct position. As default
this option is ON.
- Auto-stacking. If Auto-stack is activated, the systems stacks each
measured sample as many time as possible according to your
measurement speed. Otherwise the number of stack can be chosen
between 1 and 512 (Changed under the option Stacks).
- Screen shots, data format
- Remote control, on or off. Activated if the system is used wit a remot
- Power-Save. If the Power-Save mode is on, the screen will “turn-off”
when inactive, and by that save power
- Filters button, visible or not in the General Settings screen. See
- Signal search, made as max or threshold search
- Measurement unit (feet or meters)
- Depth scale (choose between centimetre/meter or inch/feet)
- BackLightning. The intensity of the screen light can be changed with
the Backlight option. When this value is decreased the light of the
screen decreases, which affects the battery capacity positively.
- Change trace color.
- Wheels editing. See below.
- Registration of GPS functionality.
- Data disk format. This carries out a formatting of the data disk in the
Monitor which can be needed if files cannot be erased, the disk
seems full etc. These types of problems may arise if the Monitor is
turned OFF without using the Quit option.
Software upgrade. See Chapter 10.
Restoration of predefined settings. See Below.
Restoration factory Settings. See below.
Note! By pressing
the next System settings screen is
By activating the kill-switch (mandatory under certain conditions, due to
FCC regulations, see FCC Part 15.509 stating that when working with the
high frequency antenna as a hand held and wall-scanning device, it is not
allowed to de-activate the kill-switch function, but when used as a normal
GPR, (floor scanning, shallow utility detection etc.) it’s allowed to deactivate the kill-switch). The use of a kill switch function makes the antenna
stop emitting electro-magnetic waves when the switch is released. Note
that it’s advisable to continue with the next line within 10 seconds to avoid
any time drifts of the signal. The CX system will work in the following
By default the Kill-switch is always OFF and transmitting is always
If Kill-switch is ON and a High Frequency antenna connected, the
black button on the antenna has to be held down to enable
measurements. When realizing this button the transmitting will stop
within 9 seconds.
When pressing black button on the antenna again, the measurement
can continue, and the antenna is transmitting. It should be noted that
if the antenna has been off for a longer time period, it can be
necessary to let the antenna get warm (by pressing black button for
a time) before starting the measurements.
If the Filter button is set to visible,
the General Settings menu (see
also Chapter 2) will get an extra
option, Filters.
When pressing Filters the following
screen appears:
Here it is possible to change the parameters for the two different CX filters,
the FIR filter and the Time Gain filter. If one of the buttons are pressed then
the Trace/Radagram View will show how the choice of filter parameters
affects the trace otherwise the Trace/Radagram View will show the
trace/radargram only with DC removal filter.
If the FIR switch is OFF then DC Removal filter is ON for all displayed data.
If the FIR switch is ON this filter will be applied on all displayed data
according to the settings made. The FIR filter (Finite Impulse Response
Filter) is essentially a band-pass, time domain filter, removing unwanted
noise from the signal. the default parameters 25 and 5 will be appropriate.
Observe that the setting of the option BKG Removal only affects the FIR
filter and works on a trace level as a high-pass filter. It will not affect the
background removal option in the main menu for 2D Projects.
The time gain filter is applied to compensate for the geometrical and
conductive attenuation of the signal in matter. The intensity of the filter is
set in the main menu for 2D projects while the settings are changed here.
The maximum linear coefficient can be set to max 3000 and the maximum
exponential coefficient to max 1000.
It is possible to change trace colors for radar data. By pressing the trace
color button, a drop-down list will appear. Four different palettes are
9.1 Units screen
Press Units… button to enter
unit screen.
Unit type can be SI or Imperial.
9.2 Wheel screen
Press Wheels… button to enter Wheel screen.
User defined wheel can be added, removed and changed.
Note! The predefined wheels can not be removed or modified.
Wheels with diameter larger then 15cm (5.9 in) will result in a point interval
value larger then 4mm (0.15 in).
Maximum size of wheel in 3D/Grid project must have wheel smaller then 20
cm (7.9 in).
9.3 GPS settings screen
Press GPS settings… to enter GPS Settings screen.
(only available if the GPS functionality is enabled). Here can user see
settings for communication with GPS receiver.
Pressing Restore Predefined Settings the system file in the CX restores
the following:
- All antennas and wheel parameters will be restored
- Battery level is set to 11 V
- Meters are chosen as the measurement units
By pressing Restore Factory Settings the system file in the CX is restored
from the system file default image. This is useful if the system file in the unit
has been damaged in some way.
Note! Run the “Restore Predefined Settings” if default antenna settings or
distance calibrations are missing from the CX.
10 Upgrade
The instructions below describe how to upgrade the application software of
the CX.
1. Download the file: “”. The file must be unzipped
once and then a file named “ram10img.gz” is seen, which is zipped
as well, but should remain so.
2. Copy the file “ram10img.gz” to a USB flash memory.
3. Connect the unit to a fully charged 12V power source and start it up.
Note! It’s important that the battery is fully charged to avoid power
loss during the upgrade that can cause damage of the internal
4. Select the “Quit” button on the main menu and go to the system
menu by turning the turn-push key 3 turns clockwise, 3 turns counter
clockwise and 3 turns clockwise again. A more detailed description
on this can be found in the section on system settings.
5. Insert the USB memory device in the USB slot of the CX.
6. Select the option “Software upgrade” in the system menu. The
upgrade starts and can take up to several minutes.
7. When the upgrade is done, a message is shown that the upgrade
was successful. Then press the turn-push key once and CX will be
8. Remove the USB memory from the monitor and close the rubber cap
onto the USB connector.
Use a proper USB Flash Disk or USB Flash Reader that is Linux
compatible. This is often described as: Operation System Compatibility: ..,
Linux, …. or Compatible: Linux (kernel 2.6.0 or higher)
Usually when buying a USB Flash device, it is formatted as FAT16, which
is suitable.
11 Batteries and Power supply
The Li-Ion battery pack is the standard power supply for the CX (Figure
11.1). The capacity of one battery is 12V/6.6Ah. Battery bag can use up to
4 battery packs. Standard setup is two battery packs; this gives an
operation time of approx. 6 hours. When the battery voltage has dropped
down to 10V the CX is automatically turned off. The battery should always
be stored fully charged to maximize the lifetime of the battery. Power to the
X3M can also be supplied by any other external 12V DC power source.
Figure 11.1. The Li-Ion battery pack and the battery bag (left) and the LiIon Battery charger (without power cord) (right)
The battery charger is an automatic quick charger designed for Li-Ion
batteries. The recharge up to about 80% of the full capacity goes very
quickly. However, it is recommended to keep the battery charging until it is
fully charged. The battery charger can be left on after the battery has been
fully charged. It then automatically turns into maintenance charging.
The indicator lamp on the charger gives you the following information:
Red = Charging
Green = Maintenance charging
Note! Before charging it is important to reset the internal memory of the
charger by reconnecting it to the mains supply and wait until the indicator
lamp turns off.
The CX can also be supplied by
any other external 12V DC power
source. The one MALÅ Geoscience
provides is seen at right.
12 High Frequency antennas
MALÅ High Frequency (HF) antennas are available with frequencies of 1.2,
1.6 and 2.3 GHz. The 1.2 and 1.6 GHz antennas also have an EM
(Electromagnetic) option, giving a GPR antenna with a 50/60 Hz EMlocator.
The HF antennas are most suitable for investigations were high resolution
is important, as for construction/concrete investigation, asphalt mapping,
ice thickness etc. See also Table 12.1.
Table 12.1. Approximate depth ranges for different antenna frequencies.
frequency (GHz)
Approximate Radial
Approximate max
penetration depth (cm)
[m/µs] , λc/4 [cm]
* In normal geological/construction environment absent of materials with low resistivity.
The HF antennas are one-piece radar antennas where the antenna
elements are contained in a small handheld, shielded box, which in turn
can be mounted on a wheel carriage, the HF cart. See Fig 12.1 to 12.3.
Figure 12.1 The HF antenna without the wheel carriage (1.6 GHz or 1.2
GHz with the EM option).
Figure 12.2 The HF antenna (1.6 or 2.3 GHz) in a wheel carriage, the HF
cart. Note the connections for the encoder wheel and the antenna buttons.
Figure 12.3 Mounting the HF antenna in the HF cart. The antenna is
attached to the cart on two sides, see the arrows.
The HF antennas are attached to the CX main unit through a 4 m long
cable, allowing a flexible and mobile data collection. A 10 m extension
cable is also available.
If the antenna is used without the wheel carriage, the skid plate (attached
with screws underneath the antenna box) should be changed when worn,
to insure a long lifetime of the antenna.
The antennas can also be used with a single wheel encoder, see Fig. 12.4
below, instead of the wheel carriage. This is quite convenient if the
investigation surface is rough and uneven or if the HF antenna is to be
used in another measurement direction, for instance to investigate
polarization effects.
Figure 12.4 The single wheel encoder (top) and attached to a HF
antenna (below) in two different directions.
When the HF antennas are used with the CX control unit, the data
collection can also be controlled by the two buttons on the handle of the
antenna (Fig. 12.5), or on the HF cart or extension pole. By pressing either
the black or red button the operator moves in-between the individual menus
on the screen and activates the selection by pressing the two buttons at the
same time. In 3D projects, the button on the right hand side of the handle
(black) starts and stops data collection of the current profile and the left
hand button (red) begins a new profile.
Figure 12.5
1.6 GHz antenna with the right (black) and left (red) hand
buttons visible.
Figure 12.6 Extension pole. On the handgrip the two buttons are seen,
the one on the top (red) starts a new profile.
When using the extension pole, as seen in Fig. 12.6 above, the two buttons
are located on the hand grip, with one button underneath the grip starting
and stopping the data collection, and the other one (red) on the handle top
starting a new profile.
The extension handle, with the control buttons, is mounted on the wheel
carriage or on the antenna itself and the extension handle cable is
connected to the connector at the back of the High Frequency antenna.
See Fig 12.7.
Figure 12.7
Mounting of the extension handle.
If measuring single profiles, the buttons on the antenna or the extension
handle are not in use. Note however the kill-switch on US-models.
As an option a switch box is provided to the High Frequency antennas (Fig.
12.8). With this switch box it is possible to measure with only the receiver in
one HF antenna and only the transmitter in the other HF antenna. This
enables different types of tomographic measurements and velocity analysis
as CMP (Common Mid Point). The data cables from the two antennas are
connected to the switch box and the switch box to the CX Main unit.
Figure 12.8. Switch box for two High Frequency antennas.
Technical Specifications CX unit
Pulse repetition frequency
Data bits
Time stability
Sampling frequency
Acquisition mode
Time Window
Power supply
Operating time
Charge time
Input device
Antenna compatibility
Operating temperature
Data download
Data memory
100 kHz
Better or equal than 60 ps
6-700 GHz
Grid measurements are controlled by
remote controls on antenna/handle, with
audio response
0-70 nS
External 12V DC battery
AC/DC agg. Input 100-240 AC Output
13.2 V DC / 4.5 A
6 hours
Quick charger, automatic charge cycle
100-240 V AC input
3-5 h (80-100%)
Combined turn-push button
On by start button
Off by menu and button
High Brightness (CX10) or
Transreflective 10.4” (CX11), weather
resistant (IP65)
MALÅ High frequency series:
1.2 GHz, 1.2 GHz+EM, 1.6 GHz, 1.6
GHz+EM, 2.3 GHz
410 x 210 x 55 mm + protruding details
40 mm
3.5 kg
-20 C to +50 C (-4 F to +122 F)
IP 65
USB 2.0
1 GB
14 Technical specifications HF Antennas
Centre frequency
1.2, 1.6 and 2.3 GHZ
> 100 %
Time window
> 50 ns
Repetition rate
100 kHz
EM option
50 Hz or 50/60 Hz sensors (sensitivity
300 uV, 14 bits)
160x90x110 mm (1.6 GHz and 2.3 GHz)
and 190x115x110 mm (1.2 GHz,
1.6+EM and 1.2+EM)
0.6 kg: 1.6 GHz and 2.3 GHz
1.0 kg: 1.2 GHz
1.2 kg: 1.6+EM and 1.2+EM
Cable length
Operating time
3 hours (with 12V battery)
Operating temperature
-20 to + 50 C
Control Unit
CX Main unit, ProEx or CUII control units
Data acquisition
CX Main unit or XV Monitor (both
preferred) or other laptop (with MALÅ
Ground Vision software)
Wheel cart, single wheel encoder,
Extension handle, 10 m extension cable,
split box for tomography applications
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