Carlson C-ALS HD User manual

C-ALS HD hardware manual H-5913-8500-02-C August 2023
C-ALS HD
Underground cavity scanning system
Hardware manual

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Contents
1Customer information.............................................................................................................................................................................4
1.1 Dear customer .............................................................................................................................................................................4
1.2 Head office contacts ....................................................................................................................................................................4
1.3 User manual ................................................................................................................................................................................4
2Introduction ............................................................................................................................................................................................6
1.4 Features ......................................................................................................................................................................................6
1.5 Deployment..................................................................................................................................................................................6
2Hardware components ...........................................................................................................................................................................8
2.1 Probe ...........................................................................................................................................................................................8
2.2 Extension piece .........................................................................................................................................................................11
2.3 Surface unit................................................................................................................................................................................13
2.4 Main C-ALS cable ......................................................................................................................................................................15
2.5 Slip ring drum.............................................................................................................................................................................15
2.6 Battery pack...............................................................................................................................................................................21
2.7 Alternate power cables...............................................................................................................................................................22
2.8 Ethernet cable............................................................................................................................................................................23
2.9 Boretrak rods .............................................................................................................................................................................23
2.10 Transit case ...............................................................................................................................................................................25
2.11 Gyro Calibration jig ....................................................................................................................................................................26
2.12 Alternative deployment methods ................................................................................................................................................30
3Maintenance and care of the C-ALS HD system ..................................................................................................................................31
3.1 General......................................................................................................................................................................................31
3.2 Preventative maintenance..........................................................................................................................................................31
3.3 Cleaning the C-ALS ...................................................................................................................................................................32
3.4 Storing and transporting.............................................................................................................................................................32
4Operational use ...................................................................................................................................................................................33
4.1 Software and field operations.....................................................................................................................................................33
4.2 System limitations ......................................................................................................................................................................33
5C-ALS HD Specifications .....................................................................................................................................................................35
6Safety information................................................................................................................................................................................37
6.1 Laser safety ...............................................................................................................................................................................37
6.2 Batteries ....................................................................................................................................................................................37
7Product information..............................................................................................................................................................................38

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1 Customer information
1.1 Dear customer
The C-ALS HD system is designed to be easy to operate. However, we would ask you to take the time to read these
operating instructions carefully before using the system, and to keep the manual with the instrument at all times.
For any feedback or comments, or if there are questions about the C-ALS HD system which are beyond the scope
of this manual, contact the product support department at Carlson, or your local Carlson representative.
Alternatively, for information on your local Carlson-approved service centre, visit our website at
www.carlsonsw.com.
To ensure best service, please make a note of the serial number. This can be found on a label on the C-ALS probe.
1.2 Head office contacts
Carlson Software Inc (Head office of Carlson Software)
33 East Second Street
Maysville, KY, USA 41056
[phone]
[e-mail]
Carlson Laser Measurement Devices. (Head office of Carlson LMD, manufacturing, service, and support)
Halifax House,
Tockwith,
York,
YO26 7QP,
UK
[phone]
[e-mail]
1.3 User manual
It is important that you read this manual carefully before using the instrument.
There are two manuals available with the C-ALS HD system, both of which are loaded onto the supplied Carlson
USB drive:
•This C-ALS HD hardware manual, which gives a full description of the hardware components of the C-ALS
HD system and some optional accessories.
•A Carlson Scan software and operations manual.
It is essential that the accompanying Carlson Scan software and operations manual is read and understood. As
well as describing the software, that manual gives an overview of a typical deployment. Some troubleshooting
guidelines are also offered which address the most common problems and questions that arise from users of the
C-ALS HD.
This manual has been compiled with care. However, should you discover any errors, we would be grateful if you
could contact Carlson directly. The information in this document is subject to change without notice.
Reproduction in whole or in part, including utilisation in machines capable of reproduction or retrieval, without the
express written permission of Carlson is prohibited. Reverse engineering is also prohibited.

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1.3.1 Manual version
The document number of this manual is H-5913-8500-02-C. Compiled in August 2023.
The manual is based on C-ALS HD units running firmware version 1.0.6.2 / 1.0.7.2 / 1.0.8.2.
Update log
H-5913-8500-02-C
•Updated photos to account for design changes from C-ALS Gyro to C-ALS HD.
•Added ‘Basic inspection of voids’ to camera applications (section 2.1.3).
•Changed Surface unit voltage rating (2.3).
•Added warning regarding mixing surface units for different versions of C-ALS (2.3 & 3).
•Added Sling ring drum and Slip ring drum with winch sections (2.4).
•Updated Specifications table (5).

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2 Introduction
1.4 Features
Carlson’s C-ALS HD is a ruggedised 3D laser scanning system. With a diameter of just 50 mm, the unit is designed
to be deployable through boreholes for surveys of underground voids and cavities. The C-ALS HD remotely
measures the three-dimensional shape of the void and, through the accompanying software, can produce a detailed
digital model of the surveyed space.
The instrument employs the ‘time-of-flight’ laser measurement technique to measure ranges to rock faces and other
surfaces without the need to place reflectors on the target. This allows accurate measurements to be made of
inaccessible areas such as ore passes and cavities.
A motorised 2-axis scanning head ensures a complete 360° scan covering the entire void up to a range of 150 m.
The C-ALS probe incorporates a miniature, inertial measurement unit (IMU) which contains a triaxial accelerometer,
magnetometer, and gyro. The IMU provides the C-ALS HD with an accurate heading and inclination.
An integrated borehole camera in the ‘nose’ of the unit aids deployment and placement of the scanning head.
1.5 Deployment
The C-ALS HD system is most commonly lowered along a borehole using the supplied, load-bearing main cable.
Figure 1 The C-ALS in use

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During the deployment, the main C-ALS cable provides power to the C-ALS probe and enables two-way data
communications between the C-ALS HD and a Windows tablet running Carlson Scan software.
Prior to deployment, the C-ALS probe is aligned against a known orientation on a supplied jig. This establishes a
starting, reference heading for the gyro. The known coordinate of the hole collar gives a starting location for the
survey.
Readings of the internal IMU are taken at fixed intervals as the C-ALS probe is deployed along the borehole. At
each of these intervals, information from the sensors is collected, and coordinates are calculated with reference
back to the known collar location. Thus, a picture of the path that the C-ALS probe has taken is built up. The IMU
sensors also enable accurate positioning of the unit when it is scanning and ensure that each point in the resulting
‘point cloud’ can be correctly geo-referenced.
Carlson Scan software enables the C-ALS HD to be controlled remotely by operators in a safe location. The
deployment, the borehole video and all scans can be viewed on-screen in real-time.
Carlson Scan software processes the data for editing, viewing and export to third-party modelling and CAD
packages.

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2 Hardware components
This section details the full range of components that are available in a C-ALS HD system. As various models of
the C-ALS have been produced and supplied, and the technology is constantly evolving and improving, some
components described below may not feature in every C-ALS HD system, or may differ in some way.
2.1 Probe
Laser head
(Internally) IMU
incorporating a gyro
Connection to
main cable and
extension piece
Stainless steel
body
Figure 2 C-ALS HD probe

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2.1.1 Laser head
The C-ALS probe incorporates the laser head, which contains the measuring laser module. The laser head is
constructed of lightweight aluminium.
The laser head is designed to enable full 360° coverage for all surveys. Servo-driven gear systems within the C-
ALS probe drive a pivot for both vertical and horizontal movement. Both drive systems incorporate a clutch
mechanism coupled with firmware control to minimise the risk of damage if the laser head becomes obstructed
during scanning operations.
The brake on the vertical motor is only engaged once power is connected to the probe. When power is removed
from the probe, each axis is able to rotate and will back-drive the gearing and motor. This is most noticeable in the
vertical motion, and the laser head may be seen to swing vertically as gravity pulls the laser head down on the
vertical pivot. This movement will not damage the probe drive system.
To run a full scan, the laser head requires at least 20 cm clearance from the vertical pivot, on all sides of the probe.
Note that the laser head around the camera may become hot when the C-ALS HD is powered ON with the LEDs
fully lit.
Laser head
Camera
Transmit and
Receive laser optics
Vertical pivot
Horizontal
pivot
LEDs
Figure 3 C-ALS HD Laser head and borehole camera

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2.1.2 Probe body
The probe housing is constructed of robust stainless steel. The accelerometers and optional gyro, which monitor
the inclination and heading of the probe, are contained within this housing.
A connector at the opposite end of the C-ALS to the laser head provides the connection point for the main C-ALS
power/data cable. Above this connector are alignment holes and a brass tightening nut, both of which are designed
to ensure the extension piece can be securely fixed to the probe in the correct alignment (see section 2.2).
The C-ALS serial number label is on the probe beside the main cable connection.
2.1.3 Camera
The nose of the laser head incorporates a high definition camera, which is designed to be used during the
deployment of the C-ALS probe (Figure 3). LEDs around the camera provide sufficient lighting to illuminate the
borehole in front of the C-ALS probe as it is deployed, and then up to 25 m in the void for inspection purposes.
The camera serves three purposes:
1. To gauge the distance that the probe is deployed beyond the ‘breakout’ point of the borehole. The laser
head and the rotating horizontal shaft must be deployed far enough from the borehole to ensure unrestricted
motion. However, the C-ALS probe must not be so far out of the borehole that its full length ‘flops’ into the
void. If this occurs, it may be impossible to retrieve the unit. Thus, it is critical that the unit is deployed within
these two limits.
2. To check the condition of the borehole. The camera will pick up any obstructions, blockages or ‘cave-ins’.
This can help to manage the deployment and, where necessary, to protect the C-ALS probe from potential
damage.
3. Basic inspection of voids.
The first two functions can be carried out during the deployment at the same time as IMU readings are being taken.
This negates the need to deploy a separate camera system down the borehole prior to using the C-ALS HD.
However, in some circumstances – for example, if there are concerns about the stability of the borehole – it is
Alignment holes for
extension piece
Serial
number
Brass tightening
nut
Main cable
connection
Figure 4 C-ALS HD probe end

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advisable that, prior to using the C-ALS HD, a separate camera should be deployed down the borehole. In this way
the condition of the borehole can be checked before the C-ALS probe is deployed and put at risk.
2.2 Extension piece
The extension piece is constructed of stainless steel and incorporates an adaptor for attaching Boretrak rods
(Figure 5).
The extension piece gives greater length to the probe, allowing more scope for the C-ALS HD to be held further
out into the void. It also helps to increase the stability of the probe while it is scanning.
The extension piece is attached to the C-ALS probe by aligning the two connecting pins on the extension piece with
the two alignment holes on the probe. The two brass nuts (one on the extension piece, the other on the probe) can
then be tightened around the separate cover piece (Figure 6).
Connecting
pins
Boretrak
rod adaptor
Brass
tightening nut
Connection
to C-ALS
Figure 5 C-ALS HD Extension piece

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The main C-ALS cable must be threaded through the extension piece and connected to the probe before the
extension piece is connected to the probe.
The ‘scan origin’ – to which all laser measurements and IMU readings are reduced – is inside the probe at the
vertical pivot point. From this point back to the hole in the rod adaptor is exactly 2 m.
C-ALS
probe
Extension
piece
Tightening
nut
Cover piece
Tightening
nut
C-ALS
cable
Figure 6 Attaching the cover piece
Laser head
C-ALS
probe
Extension
piece
Boretrak
rod adaptor
2m from vertical pivot
to rod adaptor
Figure 7 Complete unit with probe and extension piece

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2.3 Surface unit
The surface unit is housed in a durable, watertight ‘Peli’ case (Figure 8). It manages the communications and power
requirements of the C-ALS probe.
The surface unit incorporates four Mil-Spec connectors which accept the supplied cables (Figure 9):
•The main C-ALS cable, which connects directly to the probe. The main cable supplies power to the probe
and enables two-way data communications between the probe and the PC.
•An Ethernet cable that connects the surface unit to the PC running C-ALS control software. As an alternative
to using this cable, a Wi-Fi base unit inside the surface unit allows wireless connectivity.
•Two identical power connections to supply power to the surface unit from an external power source. Either,
or both, of these ports can be used to supply power to the unit. This allows ‘hot-swapping’ between, or
simultaneous use of, two different power sources.
The surface unit is powered from an external source of 11.5-15 Vdc. A mains adaptor (110-240 Vac input) and a
Figure 8 Surface unit
Figure 9 Surface unit connections from left to right: main C-ALS cable, data cable, one power cable and a
spare connector for an additional power cable

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cable with crocodile clip connectors are included with the system for this purpose, together with a dedicated lead
acid battery and connecting cable. All three of these power cable options fit the two power connectors on the side
of the surface unit.
Underneath the lid of the surface unit is the internal panel (Figure 10). This incorporates the ON/OFF switch which
powers up the C-ALS system and sends power to the probe. An LED indicates that the surface unit is switched ON.
The surface unit is fused for use with two external power sources. The fuses are located in holders mounted inside
the unit. T3.15 A anti-surge fuses are used.
The Wi-Fi antenna is housed inside the surface unit. In good conditions, the wireless datalink will work at up to 50
m if there is a line-of-sight between the PC and the surface unit.
Keep the lid of the surface unit closed during operations to maximise protection against water ingress. Closing the
lid does not affect the performance of the Wi-Fi signal.
The supplied surface unit can be used with any C-ALS HD unit. However, it should never be
used with an earlier C-ALS model such as a C-ALS Gyro, standard C-ALS or C-ALS mk3 unit.
These earlier models would have been supplied with a yellow surface unit incorporating a
LEMO connector for the main C-ALS cable.
Using a C-ALS HD surface unit with an earlier C-ALS model, will void any product warranty and
could cause serious damage to the C-ALS probe. Check the serial label on the C-ALS probe to
confirm which variety of C-ALS you are working with. Alternatively, contact Carlson for further
information.
Figure 11 C-ALS Gyro (left) / C-ALS Mk3 (centre) models should not be used with the C-ALS HD surface unit. These C-ALS
probes would have been supplied with a yellow surface unit (right).
Fuse
holders
ON / OFF
switch
Figure 10 Surface unit internal panel

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2.4 Main C-ALS cable
The main C-ALS cable delivers power to the probe, enables two-way data communications and carries the video
signal from the borehole camera.
The main cable can be supplied in various lengths, up to a maximum of 205 m. A moulded connector on one end
screws into the threaded end of the C-ALS probe. At the other end is a Mil-Spec connector. This connects either
directly to the surface unit or to the inside of the slip ring drum.
The main cable and its connectors are highly durable. The cable and the moulded connector have a breaking strain
of 500 kg.
The main cable is marked at metre intervals by alternate red and black rubber nodules to ensure regular, accurate
intervals between IMU readings as the probe is deployed into the hole.
An unmarked, 5 m section of main cable is supplied with every C-ALS system. This can be used for operations
where there is only a very short deployment necessary or to facilitate simple system tests in an office environment.
This short cable is also used to connect the optional slip ring drum to the surface unit.
By default, the main cable is supplied wound onto a simple steel drum. There is no slip ring in the drum so, before
connecting the cable to the surface unit and the C-ALS probe, unspool as much cable as will be needed for the
operation.
2.5 Slip ring drum
The C-ALS cable can be also supplied on an optional slip ring drum.
The slip ring ensures that the cable can be reeled out and hauled back in while still retaining a connection to the
surface unit.
The Mil-Spec end of the C-ALS cable attaches to a connector on the inside of the drum.
Figure 12 C-ALS main power/data cable on reel (left) and short 5m cable (right)

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The short 5 m test cable runs from the connector on the outside of the drum frame to the appropriately sized Mil-
Spec connector on the surface unit.
An ungeared handle is used to wind the cable back onto the reel.
When using any drum in the field, ensure that it is secured in place during a deployment and while a scan is taking
place.
Figure 13 Slip ring drum
Mil-Spec connector
for cable on drum
Connector for short 5 m
test cable
Figure 14 Connectors on the slip ring drum

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2.5.1 Slip ring drum with winch
A further option is a winch attachment on the side of the slip ring drum.
An inbuilt brake ensures that the reel is kept under control and holds fast under load.
To disengage the brake and allow free unspooling, fully unscrew the handle hub to expose the retaining thread.
The handle can be detached from the handle hub. This exposes a ¼” square connection point on the handle hub.
Use a battery-powered hand drill with a ¼” socket attachment to haul in the cable.
The gear ratios on the winch can be switched between 4:1 for manual winding, and 24:1 for winding with the drill.
To switch to the lower gear, push the gear lever towards the drum. Apply pressure to both sides of the gear lever
to shift between the two possible positions.
Gear lever
Handle
Handle hub
Figure 15 Winch handle and gear lever
Figure 16 Handle hub removed to allow free spooling

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Note that in order to change the gear, you may need to turn the handle until the gear lever engages. In addition, if
there is a load on the winch, you may need to briefly take the weight off the winch in order to change the gear.
Slide gear lever to
change gear
Figure 17 Sliding the gear lever to change to a lower gear
Detached
handle
¼” square connection
point on handle hub
Figure 18 Winch handle removed showing the 1/4" square attachment

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Using a drill, the winch can be raised around 13 m / minute.
Figure 19 Drill with 1/4" socket attachment
Figure 20 Using a drill to operate the winch

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Note: when using a hand drill, it should be set to the highest clutch setting in conjunction with the ‘screw’
symbol.
Do not use the drill settings showing a ‘drill bit’ or a ‘hammer’ symbol.
An incorrect selection could cause injury or damage to the equipment. It is the user’s responsibility to
select and correctly operate the drill equipment and to correctly manage