Applied Photonics LIBSCAN 25+ User manual

Portable, Modular
Laser-Induced Breakdown Spectroscopy
(LIBS) Instrument
User’s Manual
January 2018
Applied Photonics Ltd
Unit 8 Carleton Business Park, Skipton, North Yorkshire BD23 2DE, United Kingdom
Tel [phone] Fax [phone] Web: www.appliedphotonics.co.uk

© 1998 - 2018 Applied Photonics Ltd Page 2 of 23
Contents Page
1. Introduction 3
2. Safety 3
2.1 Laser radiation 3
2.2 Note on the laser safety window material used in the modular sample chambers 6
2.3 Electrical 7
3. General description 8
3.1 Overview 8
3.2 LIBSCAN 25+ instrument console 9
3.3 LIBSCAN 25+ head 10
3.4 The integrated pulsed laser 11
3.5 Laser beam expander and plasma light collection optics 12
3.6 Imaging camera and associated components 13
3.7 Attachment of the LIBSCAN 25+ head to an optical table 13
3.8 Modular sample chambers 14
4. General operating procedure 16
5. Shut-down procedure 21
6. Maintenance and inspection 21
7. Shipping and storage 21
8. Trouble-shooting / fault finding 22
Appendices
A1 EC Declaration of Conformity 23

© 1998 - 2018 Applied Photonics Ltd Page 3 of 23
1 Introduction
LIBSCAN 25+ is a fully portable Laser-Induced Breakdown Spectroscopy (LIBS) instrument adopting
the same modular design principles used in our LIBSCAN range of products. Suitable for laboratory or
field applications, LIBSCAN 25+ operates from its internal 12 Volt 8Ah Li-Ion battery and can operate
for up to 4 hrs from a single charge. Recharging is achieved using a mains plug-in adaptor Li-Ion charger
which is supplied with the instrument. The six-channel design of LIBSCAN 25+ allows for up to six
compact spectrometers to be installed (approx. 185 –900 nm), depending upon the requirements of the
intended application and budget limitations. LIBSCAN 25+ can be supplied with an optional integrated
imaging camera for recording close-up video / still images of the sample. LIBSCAN 25+ is, by design, a
Class 4 laser product although when used with one of our range of modular sample chambers the product
meets Class 1 laser safety standards.
This User’s Manual provides the necessary information needed to configure the LIBSCAN 25+
instrument and how to use it safely. It is assumed that the user will be familiar with the safety issues
arising from the use of high-power lasers and will have preferably been trained in the safe use of high-
power laser products.
2 Safety
2.1 Laser radiation
LIBSCAN 25+ contains a high-power Q-switched Nd:YAG laser (Class 4, nominally 50 mJ @ 1064 nm,
5 ns pulse length, 1 Hz pulse repetition rate) and so it is imperative that it is operated only by suitably
trained and experienced persons who are fully aware of the hazards inherent to this type of high-power
laser equipment. It is imperative also that, prior to using the equipment, an appropriate risk assessment is
conducted in such a way as to take account of the proposed use of the equipment, the environment in
which the equipment is to be operated, and how its use may affect people who are not directly involved
with the use of the equipment.
Laser product classification label
LIBSCAN 25+ is designed to meet the laser safety requirements of the relevant European standards (BS
EN 60825-1: 2014) and USA standards (ANSI Z136.1 –2014). Although LIBSCAN 25+ may be
supplied with a sample chamber which provides adequate containment of the laser radiation to Class 1
Accessible Emission Limits, it is possible for the user to operate LIBSCAN 25+ without the sample
chamber (ie. operation in “open beam” mode as may be required for certain types of experiment).
Accordingly, it is necessary to consider LIBSCAN 25+ to be a Class 4 Laser Product and so, by
definition, the equipment poses a risk of personal injury (eye, skin injury) and poses a fire risk. As with
all Class 4 laser products, appropriate safety precautions must be taken as identified via a suitable risk

© 1998 - 2018 Applied Photonics Ltd Page 4 of 23
assessment conducted by the user in consultation with a suitably qualified and experienced Laser Safety
Officer.
The most significant hazard relating to exposure of personnel to the laser radiation is eye injury since
direct or scattered laser radiation produced by LIBSCAN 25+ can cause serious and permanent injury to
the eyes including blindness - such injury may be instantaneous. Precautions must be taken to avoid
exposure of personnel to hazardous levels of laser radiation. Such precautions may include the setting up
of a temporary or permanent laser controlled area (eg. a laser laboratory). Other measures may also be
necessary, as determined by appropriate and thorough assessment of the risks (ie. a risk assessment)
conducted by the personnel responsible for the safe use of the LIBSCAN 25+ instrument.
With the use of an optional adaptor, LIBSCAN 25+ may be used with any one of our range of modular
sample chambers (SC-1, SC-2, etc). The door of the sample chamber is equipped with a dual electrical
interlock switch which is designed to prevent activation of the laser unless the door is fully closed. The
interlock circuit is designed to “fail safe” so if it is not connected properly (e.g. the LIBSCAN 25+ is not
correctly attached to the modular sample chamber using the supplied adaptor), the interlock circuit is
designed to prevent activation of the laser. Removal of the sample chamber from the LIBSCAN 25+
head will also activate the interlock (i.e. prevent activation of the laser). The key-switch operated
Interlock Override (see section 3.2 of this User’s Manual) allows the safety interlock feature to be
disabled. It is necessary to use this override feature when operating the LIBSCAN 25+ without a sample
chamber (i.e. operating in “open beam” mode). In view of this, the LIBSCAN 25+ system must be
categorised as a Class 4 laser product since, by design, the product may be used in such a way that the
laser beam is not contained (i.e. “open beam” mode of operation).If, however, the sample chamber is
correctly fitted to the LIBSCAN 25+ head and the Interlock Override is switched off and the key
removed, then the laser radiation is adequately contained to Class 1 Accessible Emission Limits by the
design of the hardware. You should consult your Laser Safety Officer to ensure that this meets any local
rules and regulations concerning the operation and use of Class 4 laser systems within your organisation.
Class 4 laser interlock warning label

© 1998 - 2018 Applied Photonics Ltd Page 5 of 23
IMPORTANT
READ and UNDERSTAND this User’s Manual before operating the LIBS equipment.
ENSURE that an appropriate risk assessment has been conducted to establish whether or not the laser safety windows
fitted to the modular sample chambers provide adequate protection against exposure to laser radiation for the specific
laser you intend to use with the LIBS equipment. For advice on this matter, consult your Laser Safety Officer
and/or Applied Photonics Ltd.
ONLY suitably qualified and authorised persons should activate the Interlock Override keyswitch. The key should be
removed from the keyswitch and held by the Laser Safety Officer when this feature is not required.
ALWAYS use appropriate laser safety protective eyewear when operating the LIBS equipment in “open-beam”
configuration –you should seek advice from your Laser Safety Officer on this matter.
ALWAYS switch the laser off when not in use and remove the key from the keyswitch of the laser power supply to
prevent unauthorised activation.
ALWAYS thoroughly inspect the LIBS equipment for damage prior to use. Particular attention should be given to the
laser safety windows and the laser safety interlock system, which should be tested each time the equipment is used.
NEVER allow unauthorised and/or untrained persons operate the LIBS equipment.
NEVER operate the LIBS equipment in areas where explosive gas mixtures may be present.
NEVER operate the LIBS equipment with any access cover, panel, or protective window removed.
NEVER place inside the sample chamber flammable liquids or any other material which may give rise to flammable /
explosive gas mixtures. Activation of the laser under these conditions could result in an explosion leading to severe
personal injury and/or fire hazard. Remember that the laser-induced plasma is a source of ignition.
NEVER point the LIBS laser beam at a person (even with laser switched off), especially towards the eyes, even if the
person is wearing laser safety eyewear. The laser should be considered “active” unless the laser power supply is
deactivated and the safety shutter fitted to the LIBSCAN 25+ head is switched to the CLOSED position.
NOTE that the transparent acrylic nozzle aperture of the LIBSCAN 25+ head does not provide any protection to the
user against exposure to direct or scattered laser radiation. The function of the nozzle aperture is described later in
this User’s Manual.
CAD image of LIBSCAN 25+ head with laser safety shutter in the “closed” position.
Laser shutter / trigger guard
in “closed” position.
Orange warning light not
illuminated
Trigger guard in “closed” position preventing
access to the trigger switch. When the laser
shutter is closed, the trigger switch is
electrically isolated and so the laser will not fire
even if the trigger switch is activated. The laser
shutter provides a mechanical beam stop which
prevents emission of laser radiation under any
circumstances, including a fault condition.
Laser aperture
warning label
Laser aperture

© 1998 - 2018 Applied Photonics Ltd Page 6 of 23
CAD image of LIBSCAN 25+ head with laser safety shutter in the “open” position.
2.2 Note on the laser safety window material used in the modular sample chambers
The laser safety window material fitted to the modular sample chambers is rated as follows:
Laser
Wavelength
(nm)
USA Standard
ANSI Z 136.1 –2014
UK & European Standard
BS EN 207:2017
Optical
Density
Protection Level R
(Q-switched laser)
1064
OD 6
L6
355
OD 5
L5
266
OD 3
L3
R L6 at 1064 nm indicates a protection level of maximum spectral transmittance of 10-6 at 1064 nm for a
pulsed laser of pulse length 10-9 –10-7 seconds (ie. a Q-switched laser).
The laser safety windows used in Applied Photonics Ltd’s range of modular sample chambers provide
adequate protection against scattered laser light of wavelength 1064 nm, 355 nm and 266 nm such that
Class 1 Accessible Emission Limits are met if the sample chamber is used correctly and laser pulse
energies are not excessively high (ie. typically less than 300 mJ with a 5 - 10 ns pulse length). Note that
the protective windows are NOT suitable for use with a 532 nm laser. Given that the modular sample
chambers may be used with a variety of APL’s LIBS products, it is the responsibility of the user to
conduct a risk assessment to establish whether or not the laser safety windows provide adequate
protection for the particular laser being used. If in any doubt, you should consult your Laser Safety
Officer and/or Applied Photonics Ltd for advice on this matter.
Warning –the Applied Photonics Ltd modular sample chambers are designed specifically for use
with our LIBSCAN (and our LIBS-6 / LIBS-8 integrated LIBS modules) range of products and
should not be used with any other laser device or product. If in doubt, seek advice from the
manufacturer, Applied Photonics Ltd.
Laser shutter / trigger guard in “open”
position. Orange warning light now
illuminated (assuming laser is active)
Trigger guard in the
“open” position allowing
access to the trigger switch

© 1998 - 2018 Applied Photonics Ltd Page 7 of 23
2.3 Electrical
The majority of internal electrical components within the LIBSCAN 25+ instrument operate at a nominal
voltage of 12 VDC at a maximum current of approximately 3.0 Amp. The integrated laser and associated
power supply operate at voltages of up to 1000 VDC. Accordingly, there exists an electric shock risk
should the equipment be dismantled. There are no user serviceable components within the LIBSCAN
25+ instrument and so the equipment should not be dismantled (doing so will void the warranty and
expose the user to an electrical and/or laser radiation hazard). For servicing and repairs, the equipment
should be returned to the manufacturer or an authorised agent.

© 1998 - 2018 Applied Photonics Ltd Page 8 of 23
3 General description
3.1 Overview
The main components of LIBSCAN 25+ are illustrated in the following figure.
CAD image illustrating the main components of the LIBSCAN 25+ instrument
The instrument console contains the optical spectrometers (up to six spectrometers may be installed), the
laser power supply, the Li-Ion battery, and various electrical / electronic components. The LIBSCAN
25+ head contains the laser, the laser beam expander optics, the plasma light collection optics, a miniature
colour video camera (optional item) and various other components associated with the safe operation of
the equipment. The LIBSCAN 25+ head is permanently connected to the instrument console via a
flexible umbilical of length ~1.6 metres. The umbilical contains the optical fibres used to transmit the
plasma light to the spectrometers, and the electrical cabling for the laser and other electrical components
within the head. The control panel provides the various switches and electrical connections associated
with the operation of the instrument.
Instrument
console
LIBSCAN 25+
head
Control panel
Flexible
umbilical
Li-Ion battery
charge status
indicator

© 1998 - 2018 Applied Photonics Ltd Page 9 of 23
3.2 LIBSCAN 25+ instrument console
Main “Power On” switch –
central indicator light flashes
when unit is connected to
mains charger
Laser key
switch (key
not shown)
“INTLK IN” BNC for
connection to laboratory door
interlock device. Blanking cap
(shown fitted) used if this
feature is not required
Spectrometer / laser
trigger sync
(BNC connector)
Laser flashlamp
voltage adjust
Inert gas inlet port
(requires 4 mm OD
plastic tubing) for gas-
purge of sample
“INTLK OUT” BNC
connection –provides 12
VDC output when laser is
active
Laser Interlock Override
keyswitch (for operation
as a Class 4 laser product)
USB 2.0
connection
DC power input from
plug-in Li-Ion battery
charger
Trigger input BNC to
remotely fire the laser
(requires > 0.1 millisecond
pulse of 9 –12 VDC,
centre pin +ve)
Power On
indicator lamp
Main Fuse
3A
Fuse panel
cover
Laser On
indicator
lamp
Battery fuse 1
(3A anti-surge)
Battery fuse 2
3A anti-surge
Laser pulse counter

© 1998 - 2018 Applied Photonics Ltd Page 10 of 23
3.3 LIBSCAN 25+ head
The LIBSCAN head contains the laser and associated optics required to focus the laser beam on to a
sample and collect the plasma light for transmission to the spectrometers located within the spectrometer
console. The head is also designed to accommodate a miniature CCD camera and associated components
used with the optional imaging kit. The main features of the LIBSCAN head fitted with the optional
imaging kit are illustrated in the following figures. Use of the transparent aperture nozzle allows the
operator to view the laser plasma even when a sample is placed up against the aperture.
WARNING: Note that the transparent aperture nozzle does NOT provide any protection to the
user against exposure to the laser radiation.
It is not necessary to have an aperture nozzle fitted to the LIBSCAN head although it is beneficial to do
so as it provides the following functions: i) facilitates correct positioning of the sample being analysed, ii)
helps to direct the purge gas (if used) to the region in space where the laser plasma will be formed, and
iii) provides protection for the optics etc against accidental mechanical damage.
LIBSCAN 25+ head with aperture nozzle removed LIBSCAN 25+ head with transparent aperture nozzle fitted
Front view of LIBSCAN 25+ head showing six-channel plasma light collection lens array,
CCD camera, LED lights, laser aperture and gas purge outlet
Grub screw for locking
transparent aperture nozzle
(do not over-tighten)
Circular array of six
lens holders –used to
collect plasma light.
The purple lens holder
is for collection of
deep UV. The blue
lens holders are for
collection of UV-VIS
while the red lens
holders are for
collection of VIS-NIR
Laser beam
expander and
output aperture
Transparent
aperture nozzle
Miniature CCD
camera
(optional feature)
Two high-
brightness white
LED lights
(optional feature)
Gas purge
outlet
Electrical connection
to modular sample
chamber

© 1998 - 2018 Applied Photonics Ltd Page 11 of 23
3.4 The integrated pulsed laser
The integrated laser is a passively Q-switch Nd:YAG operating at 1064 nm with a nominal output pulse
energy of 50 mJ. The actual output pulse energy will vary from laser to laser and may be as high as 70
mJ. The shot-to-shot variation in pulse energy is typically 10%. Note that it is not possible to adjust the
laser pulse energy. These three features are characteristic of the design of the laser. Provision has been
made for the user to adjust the flashlamp voltage (10-turn potentiometer with dial indicator located on
control panel of instrument console) so that the voltage may be increased if necessary as the flashlamp
degrades with use. If the flashlamp voltage is too low, the laser will not fire even if the flashlamp fires.
If the voltage is too high, the laser will start to operate in double-pulse mode in which case each “fire” of
the laser will generate two pulses each of nominally 50 mJ and with a variable inter-pulse separation of
some tens of microseconds. If measured using an appropriate energy meter, the double pulse output will
appear to be a single pulse of energy 100 –140 mJ. Hence the laser classification label affixed to the
LIBSCAN 25+ instrument console states a maximum energy of 150 mJ. When operating in double-pulse
mode, the spectrometer(s) are triggered by the leading edge of the first pulse. This means that the spectra
recorded with the laser operating in double-pulse mode will generally have i) much higher intensity and
ii) an elevated intensity of baseline in the form of a broad continuum (due to Bremsstrahlung radiation).
This is a direct consequence of the spectrometers being triggered from the first laser pulse rather than the
second pulse. The following spectra are typical examples obtained with LIBSCAN 25+ operating in
single-pulse and double-pulse mode.
LIBS spectrum of graphite in argon (single-pulse mode)
LIBS spectrum of graphite in argon (double-pulse mode)
Ca (393.3, 396.8, 422.6 nm)
(present as an impurity
in the sample)
C (247.8 nm)
C (193.1 nm)
Continuum due to
Bremsstrahlung radiation

© 1998 - 2018 Applied Photonics Ltd Page 12 of 23
Although the laser is able to fire at a pulse repetition rate of 1 Hz, it is recommended that the laser is
operated at not more than approx. 0.5 Hz in order to prolong the life of the flashlamp. If the laser is
operated at above 0.5 Hz, it must not be operated for more than approximately 60 pulses without allowing
a cool down period of at least 1 minute. Failure to adhere to this procedure will result in the laser
overheating which will degrade performance and will reduce the life expectancy of the flashlamp. If
operated correctly, the flashlamp can be expected to have a lifetime of up to approximately 300,000
pulses. Replacing the flashlamp requires the LIBSCAN 25+ instrument to be returned to the
manufacturer.
3.5 Laser beam expander and plasma light collection optics
The optical configuration used in the LIBSCAN 25+ system is illustrated schematically in the following
diagram. The laser beam expander consists of three lenses and is used to provide a tightly focussed laser
beam at nominally 90 mm from the aperture of the beam expander. The brass tubular piece which houses
the beam expander lenses is threaded so that rotating it causes the focal plane of the laser beam to move.
A special tool is used to rotate the brass tubular piece after first removing the nozzle aperture for access.
The design allows for approximately ±7.5 mm of adjustment, as illustrated in the following diagrams.
The plasma light collection optics are angled at approx. 15.7 degrees and are designed to collect light
from the region in space defined in the following diagram. The transparent aperture nozzle is threaded so
that rotation causes it to move along the optic axis of the laser beam –range of travel is approximately
±7.5 mm (it may be removed from the body of the LIBS module by unscrewing further). The main
purpose of the transparent aperture nozzle is to provide a convenient means of setting the distance to the
sample surface. The nozzle aperture also provides containment of the purge gas to ensure the sample
surface and laser-induced plasma region are effectively purged of atmospheric air, and provides physical
protection for the laser and plasma light collection optics (and imaging camera if fitted).
Adjustment range of focal
plane of laser beam
(approx. ±7.5 mm)
Adjustment range of
transparent aperture nozzle
(approx. ±7.5 mm)
Transparent
aperture nozzle
Brass holder
containing laser beam
expander lenses
Threaded section
Threaded section
Laser Beam
Laser Beam
Fibre-optic cable
to spectrometer

© 1998 - 2018 Applied Photonics Ltd Page 13 of 23
3.6 Imaging camera and associated components
The imaging camera is offered as an optional feature for LIBSCAN 25+. A miniature colour CCD
camera is installed inside the LIBSCAN head and is located within the black tubular holder at the 12
o’clock position at the front of the head. The tubular holder is fitted with an optical filter to protect the
CCD camera from damage due to possible high levels of stray laser light (1064 nm). The video output of
the camera is internally connected to the USB port via a USB frame grabber.
The specifications for the miniature CCD camera are:
1/3-inch CCD colour sensor (474,000 pixels)
Field angle: approx. 24º
Micro f = 12 mm lens
Adjustable focus (approx. 20 mm to infinity)
0.01 Lux F 2.0
12 VDC (65 mA)
3.7 Attachment of the LIBSCAN 25+ head to an optical table
LIBSCAN 25+ is supplied with an removable foot which may be used to facilitate mounting of the
LIBSCAN 25+ head to an optical table (metric or imperial). The following schematic diagrams illustrate
how the removable foot fits to the LIBSCAN 25+ head.
Removable foot assembly
Close-up view of laser beam focus and field-
of-view of plasma light collection optics
±7.5 mm
±7.5 mm
Laser Beam
White plastic insert –fitted
to foot to protect base of
LIBSCAN 25+ handle
from being scratched
Aluminium foot
M4 fastener to secure
plastic insert inside foot

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3.8 Modular sample chambers
A range of modular sample chambers is available for use with the LIBSCAN range of LIBS instruments
(see table below). These sample chambers are also suitable for use with our LIBS-6 and LIBS-8
integrated LIBS modules. LIBSCAN 25+ requires an adaptor which provides a mechanical and electrical
interface between the LIBSCAN 25+ head and the modular sample chamber –please see information
provided on the following page.
SC-1
SC-2C
SC-2M
SC-2L
Single axis translation stage, 20
mm travel per stage (manual
control).
Approx. overall dimensions: 110 x
120 x 200 mm
2-axis translation stage, 20 mm
travel per stage (manual control).
Approx. overall dimensions: 110 x
120 x 250 mm
2-axis translation stage, 20 mm
travel per stage (manual control)
Fume extract port. Internal LED
light.
Approx. overall dimensions: 170
x 170 x 270 mm
3-axis translation stage, 50 mm
travel per stage (manual control).
Fume extract port. Internal LED
light.
Approx. overall dimensions: 260 x
260 x 320 mm, 13.5 kg
SC-2XL
XYZ-750
XYZ-2500
3-axis translation stage, 50 mm
travel per stage (manual control).
Fume extract port. Internal LED
light.
Approx. overall dimensions: 330 x
360 x 430 mm, 18 kg
3-axis motorised translation stage
(computer controlled), 75 mm
travel per stage. Fume extract port.
Internal LED light.
Approx. overall dimensions: 330 x
360 x 430 mm, 19 kg
3-axis motorised translation stage (computer controlled), X = 250 mm,
Y = 250 mm, Z = 100 mm. Fume extract port. Internal LED light.
Approx. overall dimensions: 470 x 770 x 730 mm, 56 kg
A selection of the current range of modular sample chambers manufactured by Applied Photonics Ltd
Removable foot with four
fixing holes for securing to
an optical table
Four M5 x 20 mm
countersunk screws

© 1998 - 2018 Applied Photonics Ltd Page 15 of 23
WARNING
The modular sample chambers described above are designed specifically for use with our LIBSCAN
range of modular LIBS systems and our LIBS-6 / LIBS-8 integrated LIBS modules. The specifications
for the laser safety windows are as follows:
Laser
Wavelength
(nm)
USA Standard
ANSI Z 136.1 –2014
UK & European Standard
BS EN 207:2014
Optical
Density
Protection Level R
(Q-switched laser)
1064
OD 6
L6
355
OD 5
L5
266
OD 3
L3
R L6 at 1064 nm indicates a protection level of maximum spectral transmittance of 10-6 at 1064 nm for a
pulsed laser of pulse length 10-9 –10-7 seconds (ie. a Q-switched laser).
Adaptor for fitting LIBSCAN 25+ head to an SC-2L modular sample chamber.
The adaptor is suitable for other sample chambers manufactured by Applied Photonics Ltd
Adaptor with four M4
cap head fixing screws

© 1998 - 2018 Applied Photonics Ltd Page 16 of 23
4. General operating procedure
Step 1
Install LIBSoft on a suitable computer. Once the software is installed, connect the computer to the USB
2.0 port located on the control panel of the LIBSCAN 25+ instrument console (see illustration below).
The remainder of this operating procedure relates to the LIBSCAN 25+ hardware and not the LIBSoft
software. LIBSoft has a comprehensive Help File accessible via the software and has a User’s Manual, a
copy of which is supplied with the LIBSCAN 25+ equipment.
Step 2
The Li-Ion battery (12 VDC, 8 Ah) is fitted to the LIBSCAN 25+ instrument console and so the unit is
ready to power up. The main power on switch on the instrument console (see illustration below) is used
to activate the instrument. Before switching the instrument on, the laser key switch should be switched to
the OFF position (ie. key in vertical position - key can only be removed when in the OFF position). The
use of a separate switch for the laser allows the user to activate the spectrometers without having to
activate the laser. The use of a key switch for activating the laser is a necessary safety precaution and
meets the relevant safety standards for Class 4 laser products.
If you have a laser laboratory door interlock system, you may wish to connect the LIBSCAN 25+
instrument to your interlock system using a BNC lead which connects to the “INTLK IN” port on the
console (see following illustration). You will first need to remove the blanking cap which is fitted to the
“INTLK IN” port.
Note 1: The “INTLK IN” port needs to be in a closed circuit (ie. shorted) condition before activation of
the laser is possible. The blanking cap is used to achieve this condition when the LIBSCAN 25+
instrument is not connected to an external laser safety interlock system. The “INTLK OUT” port
provides a 12 VDC output (centre pin +ve) whenever the laser is switched on via the key switch. This
port may therefore be used to illuminate an appropriate warning light or drive a relay. Current drain from
this port should be limited to less than approx. 250 mA –the current is ultimately limited by the main
fuse (3 Amp Anti-Surge) fitted to the LIBSCAN 25 instrument console.
Note 2: The “FLASHLAMP VOLTAGE” control is factory set to a scale reading of approximately 700 –
the exact setting varies from unit to unit and is specified in the Test Report provided with the LIBSCAN
25+ instrument. Note that the scale reading (ie. 0 to 1000) does not equate to actual voltage (the
adjustable voltage range is approximately 500 to 1000 Volts DC). Decreasing the flashlamp voltage will
eventually result in the laser not firing while increasing the flashlamp voltage will eventually result in the
Main “Power On”
switch –red indicator
light illuminates when
unit is switched on
Laser key switch
(key not shown)
Blanking cap
fitted to
“INTLK IN” port
USB 2.0
connection

© 1998 - 2018 Applied Photonics Ltd Page 17 of 23
laser operating in “double-pulse” mode (ie. 2 pulses of approx. 50 mJ each, separated in time by some
tens of microseconds). Note that this type of “double-pulse” operation is not generally suitable for LIBS
measurements.
IMPORTANT: The flashlamp voltage should not be adjusted from its factory setting unless there
is a good reason to do so. Contact Applied Photonics Ltd for advice on this.
Note 3: The BNC port labelled “LASER FIRE” provides the user with the option of remotely firing the
laser as opposed to normal method of firing the laser using the switch located in the handle of the
LIBSCAN 25+ head. The “LASER FIRE” BNC port may be activated by a voltage pulse of approx 0.1
milliseconds or longer and of amplitude 9 to 12 VDC (centre pin +ve). Note that the absolute maximum
voltage applied to this port must be limited to 12 VDC. The port labelled “TRIG IN/OUT” may be used
in two ways as follows. When the laser is not used, the spectrometers may be triggered from an external
source by connecting a TTL compatible trigger to the “TRIG IN/OUT” port. When the laser is being
used, the “TRIG IN/OUT” port provides a TTL pulse which is synchronised with the laser pulse (it is the
same pulse that is used to trigger the spectrometers located within the LIBSCAN 25+ instrument
console).
Note that in normal use, the “LASER FIRE” BNC port and the “TRIG IN/OUT” BNC port are not
used but are provided for diagnostic purposes and also for more advanced experiments –contact
Applied Photonics Ltd should you be interested in using LIBSCAN 25+ with other equipment.
Step 3
As LIBSCAN 25+ may be operated using its internal Li-Ion battery, it is not necessary to connect the unit
to an electrical power source unless the battery is depleted. For laboratory use, however, it is
recommended that the plug-in Li-Ion battery charger is connected to the instrument so as to keep the Li-
Ion battery in a fully-charged state, however, to avoid the possibility of over-charging the Li-Ion battery
the charger should not be left connected to the LIBSCAN 25+ instrument for longer than approx. 8 hrs
when the instrument is not in use (ie. switched off). The charge status of the internal Li-Ion battery may
be checked by depressing the button located on the side panel of the instrument console and viewing the
indicator lights via the window, as illustrated below.
Li-Ion battery
charge status
indicator
Press black button
to activate status
indicator lights
2 Reds + 3 Greens: 75 - 100% capacity
2 Reds + 2 Greens: 50 - 75% capacity
2 Reds + 1 Green: 20 - 50% capacity
2 Reds*: 10 - 20% capacity
1 Red** : Less than 10% capacity
No lights***: Empty
* Recharge as soon as possible
** Battery is about to electronically switch off to prevent over-discharge
*** Recharge within 12 hours

© 1998 - 2018 Applied Photonics Ltd Page 18 of 23
Step 4
Make sure that the laser shutter on the LIBSCAN 25+ head is in the closed position as shown in the
following illustration.
Step 5
LIBSCAN 25+ may be used without the sample chamber if required. Under these conditions, the laser
beam is not contained (ie. the equipment is a Class 4 laser product) and hence additional safety
precautions must be observed including the use of appropriate laser protective eyewear and operating
LIBSCAN 25+ in a suitable controlled environment (eg. a laser laboratory).
IMPORTANT - it is the responsibility of the user to conduct an appropriate risk assessment prior
to using LIBSCAN 25+ in open-beam mode.
If the LIBSCAN 25+ instrument is to be used without a sample chamber (ie. operation in “open beam”
mode), it is necessary to activate the interlock override keyswitch. When this keyswitch is activated,
LIBSCAN 25+ is a Class 4 laser product and so all appropriate laser safety precautions must be observed.
A yellow / orange flashing indicator lamp located next to the interlock override keyswitch warns the user
that the interlock override keyswitch has been activated and that the LIBSCAN 25+ is operating as a
Class 4 laser product.
Laser shutter / trigger guard in
“closed” position.
Orange warning light not illuminated
Laser shutter /
trigger guard in
“closed” position
Trigger
switch
Laser Interlock
Override keyswitch
Warning light –flashes
yellow / orange when
interlock override
keyswitch is activated.
NOTE
LIBSCAN 25+ is a
Class 4 laser product
when this keyswich is
activated

© 1998 - 2018 Applied Photonics Ltd Page 19 of 23
Step 6
After taking appropriate laser safety precautions (don safety goggles, etc), switch the laser key switch to
the ON position. The LASER ON light on the instrument console should now be illuminated, as will the
blue (or orange) LED light ring and white LEDs surrounding the laser aperture –assuming the dimmer
control is not set to its lowest brightness position (see following illustration).
Step 7
Press the laser beam shutter / trigger guard upwards as shown in the following diagram. The orange
warning light will protrude from the body of the LIBSCAN 25 head and will be illuminated. The laser is
now armed and ready to fire.
Step 8
Check operation of the laser by placing a sample (eg. a metallic object) directly in front of the acrylic
aperture nozzle and then activating a single pulse of the laser by pressing the trigger switch. A laser
plasma should be produced on the surface of the sample.
Laser shutter / trigger guard in
“open” position.
Orange warning light now illuminated
Press laser shutter /
trigger guard
upwards to the
“open” position
White LEDs located
around laser aperture –
used for illuminating
sample surface
Blue LED light ring
(later models have an orange LED light ring so as
to act as an additional laser warning indicator)
Laser-induced plasma on
surface of metal sample
Dimmer control to control
brightness of white and
blue (or orange) LEDs

© 1998 - 2018 Applied Photonics Ltd Page 20 of 23
Note that on firing the laser, the orange warning light will go out for approx 1 second. During this time
the laser is inhibited and so pressing the trigger will not fire the laser. An internal time delay circuit
ensures that the repetition rate of the laser is limited to less than approx. 1 Hz. It is necessary to wait until
the orange warning light is illuminated before firing the laser.
Step 9
Switch the laser off by closing the shutter / trigger guard (press down on the orange warning light) and
turning the keyswitch on the instrument console to OFF. All lights on the LIBSCAN 25+ head should
now be extinguished.
Step 10
In order to obtain best performance from the LIBSCAN 25+ instrument, it is recommended that an argon
gas purge is used. The pressure must be limited to less than approximately 5 psi and flow-rate is typically
a few litres per minute. If argon gas is not available, it is recommended that either nitrogen or air purge is
used. Note that if no gas purge is used, particulates arising from laser ablation of the sample will
accumulate within the transparent “nose cone” aperture and may result in a deterioration of quality of the
recorded spectra due to attenuation of the laser beam and/or obstruction / absorption of plasma light.
Accordingly, we strongly recommend that the gas purge feature is used during operation of the LIBSCAN
25+ instrument.
CAD view of LIBSCAN 25+ head showing method for adjusting position of aperture nozzle.
Note that the position of the aperture nozzle will have been correctly set by the manufacturer.
Distance may be adjusted by
several mm by rotating the
aperture nozzle. Use this feature
to set position of aperture nozzle
to facilitate correct positioning
of the sample surface
Locking screw.
Do not over
tighten