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