ED-XRF- SCREENING ANALYSIS FOR ALL

ED-XRF- SCREENING ANALYSIS FOR
ALL HAZARDOUS SUBSTANCES
TAN TECK BENG
SHIMADZU ASIA PACIFIC
XRF THEORY
AND
BASIC INSTRMENTATION
Why use X-ray Fluorescence
Spectrometry?
1. Good sensitivity and wide concentration range–
from ppm to 100%
2. A high precision analysis method – It has
beendesignated by the JIS, ANSI, and DNI
Standards for analyzing inorganic materials
(iron & steel/ non-ferrous/ ceramics).
3. Rapid analysis is possible without complex
sample preparation.
4. Metals, powders, ceramics, rubber, plastics,
and liquids can be measured directly.
5. Non Destructive Analysis
Features of ED-XRF Spectrometers
• Non-destructive rapid analysis (1 to 5 min) with no
sample pretreatment
• Wide element range (all elements from Na to U)
• Wide concentration range (from a few ppm to 100%)
• FP quantitative analysis without using standards
• Accurate quantitative analysis
using standard samples also
possible
• Qualitative analysis possible
• Compact body with 100V power
supply; no cooling unit required
• Lower Instrument cost and easier maintenance than
WD-XRF
Principle of XRF
Non destructive : X-ray is used for excitation and detection
SAMPLE CONSIDERATION
Area of Analysis Possible by ED-XRF
Analysis area: average of
1, 3, 5, and 10mmφ areas
Analysis depth varies depending on
the sample and elements analyzed.
Approx. 5mm for Cd in PVC
1mm
3mm
5mm
10mm
Ti
As
Cd
How Sensitive is ED-XRF?
The minimum detectable quantity will vary depending on the
sample material.
The reasons for this variation are as follows.
a) X-ray fluorescence emission from target elements is absorbed by surrounding
materials.
b) Primary x-rays from the x-ray tube are absorbed by the surrounding material
and do not excite the target elements.
Generally high atomic number materials absorb more x-ray than low atomic
number material. In addition, absorption also increases if the material has a
higher density. Therefore, in general, sensitivity is higher in plastics and lower
in metals, as shown in the example below.
Relative Sensitivity by Materials
Variation in Sensitivity for Different Materials
X-ray intensity / calibration curve
I=I [element, content, matrix element, material, size, form,
thickness, measurement conditions (diameter, energy,
time…), and ...]
Make
Liquid
material, size,
X ray
form,
Resin
intensity
thickness and
measurement
Metal...
conditions
constant
Normally
I=I [element, content, matrix]
0 Quantitative value
Content (%, ppm)
Influence of Size and Shape on the Sensitivity
and Precision
Differences in Sensitivity Due to Sample Size or Thickness
Theoretically, the larger the sample, the greater is the x-ray intensity. This also
applies to thickness.
X-ray intensity is greater for thicker samples.
<Collimator Size>
The x-ray irradiation diameter can be changed using an optional collimator.
Using a smaller diameter for analysis generally decreases x-ray intensity levels.
However, for samples comprised of differing sections, this can reduce the
undesirable x-rays emitted from non-target areas, improving the relative
sensitivity for the target area.
Variations in X-ray Intensity due to Sample
Thickness
Intensity
When analyzing Cd in
plastics X-ray intensity
increases until a thickness
of approx. 5mm.
When analyzing a thin
sample, stack several
layers of it.
Samples which cannot be
stacked must be corrected
for thickness.
Thickness
Maximum Sample Depth in Difference Materials
Concept and Current Stream on
Testing Methods of IEC* for RoHS
IEC63231 – Procedures for the Determination of
Levels of Six Regulated Substances Lead,
Mercury, Hexavalent Chromium,
Polybrominated Biphenyls,
Polybrominated Diphenyl Ethers) in
Electrotechnical Products
* International Electro technical Commission
IEC
International standardization of testing methods for RoHS
International standardization of Testing methods for RoHS are under developing by
IEC.
Because Ｉ Ｅ Ｃ does not have TC for environmental issue,new
environmentalTC(TC111)was founded in March 2005.officer is from Italy,convener
is Mr.Mori from Fujitsu。
TC-111 consists of 3ＷＧ.Main theme are as follows;
WG-1：Material Declaration
WG-2：Environmentally Conscious Design
WG-3：Test methods of hazardous substances
By METI7s guidance JEITA(Japan Electronics and Information Technology Industries Association)was
assigned to Secretariat and founded technical committee in Japan for ＷＧ３、
Dr.Chiba, National Institute of Advanced Industrial Science and Technology,assigned
as chief examiner Convener is Mr.Markus Stutz,from German Motorola Ｗ Ｇ 2
Mr.Ichikawa was assigned to convener as per request from Japan. Foundation of WG
１ was delayed,but actual working have already started in JGPSSI(Japan Green Procurement
Survey Standardization Initiative)and started discussing for developing a global standard
alliance With Ｅ Ｉ Ａ (The Electric Industries Alliance)and Ｅ Ｉ Ｃ Ｔ A(European Information &
Communications Technology Industry Association)
IEC
Schedule onward
•
•
•
•
•
End Oct.2005 Domestic WG discussing countermeasure
End Nov.2005 Draft amendment completion
Dec.2005 Presenting Draft across member states
July 2006 Final Voting.
Oct 2006 To be Publish and make available as a
Technical Standard.
• According to response from each member states, they
should discuss whether they hold final vote for
international standard in the form of CDv(Committee
Draft for voting) or need further amendment .
IEC
Overview of Testing methods and Screening For RoHS
・ＩＥＣ Testing Methods are basically 2 stages methods consist of screening
by XRF spectroscopy and other precise quantification methods which referred to
testing methods developed by JBCE for Ｅｕenvironmental Committee.
・Under consideration that it is difficult for screening by XRF to get standard
samples and sample pretreatment in-site, detection by qualitative analysis is a
basic method. When standard samples available,quantitative analysis should be
done. In that case international approved materials is not essential.
・At the phase of screening by EDX ,EDX and WDX are recommendable, but
non-dispersive type cannot be used.
・On condition that IEC Testing method should not step into the legal
definitions and interpretation on RoHS , materials are to categorized into 3 types.
In the Working Draft they are Polymer,Metal,Electronics.）
Especially testing method of non-homogeneous electronics（PWB/Component
ｓ）should be further discussed.
Outline of RoHS testing method by IEC
＜IEC62321＞－
－
recommendable analysis
In the measurement flow under review, it is possible to choose a testing method among non-destructive/destructive
testing and qualitative/quantitative analysis as screening measurement of x-ray spectroscopy, according to introduced
equipments, standard of quality management, condition of getting standard sample.
Yes
Nondestructive
Sample
Preparation
Sample
Uniform？
Samples
Metallic
Materials
Polymer
Materials
Electronics
（PWB／
Component
Yes
Ｎｏ
《Flowchart of
Screening
Procedure
Mechanical
Sample
Preparation
the Test Procedure》
Meets
Limits？
Yes
Screening?
Pass Entity based
Further
testing？
Conforming
Sample
Ｎｏ Entity based
Non Conforming
Sample
Pass
Ｎｏ
Mechanical
Sample
Preparation
Verification Test
Procedure
Various Methods
* On the assumption that of testing methods of IEC don’t step into
legal definition and interpretation of RoHS, materials are classified
into 3 (polymer metal electronics) in working draft. Specially, it is
needed to discuss about testing method of heterogeneous
electronics(PWB/components) that are not originally
homogeneous.
Entity based
Conforming
Sample
Sample
Uniform？
Fail
Entity based
Non Conforming
Sample
Decision criteria will
Be entity based
Ｄｅｃｉｓｉｏｎ
Outline of RoHS testing method by IEC
＜IEC62321＞－
substance
Specified
Brominated
Flame Retardant
（PBB／
PBDE）
Hexavalent
Chromium （Ｃ
ｒ6+）
Mercury （Ｈ
ｇ）
polymer
chemistry
materials
recommendable analysis
－
Electronic parts
Metal materials
ＧＣ／ＭＳ
ＨＰＬＣ＋Ｕ
Ｖ
ＮＡ
ＧＣ／ＭＳ
ＨＰＬＣ＋ＵＶ
Alkali extraction
Absorption
spectrophotomet
ry
ICP-AES／MS
CVAAS、AFS
Spot test
Heat water extraction
Absorption
spectrophotometry
ICP-AES／MS
CVAAS、AFS
Alkali extraction
Absorption
spectrophotometry
Lead／
ICP-AES／MS ICP-AES／MS
Cadmium
AAS
AAS
（Ｐｂ／Ｃ
ｄ）
GC-MS：Gas Chromatography Mass Spectrometry、HPLC：High
ICP-AES／MS
CVAAS、AFS
ICP-AES／MS
AAS
Pressure Liquid Chromatography with
Ultraviolet Detection、ICP-AES：Inductively Plasma Atomic Emission Spectrometry、ICP-MS： Inductively
Plasma Ｍａｓｓ Spectrometry、（CV）AAS：（Cold Vapor）Atomic Absorption Spectrometry、AFS：A
Fluorescence Spectrometry
Analytical Methods
Screening analytical method（sample pre-treatment not needed in principle)
Analytical accuracy is inferior to destructive analytical method but suitable c in site analysis
‹ ED-XRF
Energy Dispersive X-ray fluorescence
‹ WD-XRF
wavelength dispersive x-ray fluorescence
screening ６substances（５elements）
It can analyze higher sensitive/higher accurately than EDX ,but rather difficult to make a sample
preparation
Precise analytical methods
（need sample pre-treatment such as dissolution ,extraction etc.）
sample pre-treatment is condition to dissolution, extraction. In case of deposition
（Pb),volatilizing（Hg),value number change(Cr6＋),it will be difficult to analyze precisely. In
operation of scaling、addition, sufficient care by experts should be needed to prevent equation.
‹ ICP-AES
‹ ICP-MS
‹ AAS
inductively coupled plasma atomic emission spectroscopy
inductively coupled plasma mass spectrometry
Atomic absorption spectrometry
‹ GCMS
gas chromatography/mass spectrometry
‹ UV/VIS
ultraviolet/visable spectrometry
accurate analysing of Cd、Hg、Pb～need make solution
need to abstract PBB/PBDE from resin
need extract Cr6＋
RoHS
１． Maximum Concentration Values→
The present situation is from the latest
information of TAC.
・Decision of the values are given by the EC Environment Council in December 2003.
The decision about including the Maximum concentration values based on homogeneous
material is prepared.
・‘Homogeneous material’ means a materials that cannot be mechanically disjointed into
different materials. (be not included in decision but explained in guidance)
・‘Unit’ is changed into ‘material’, therefore, definition of ‘unit’ is deleted.
・‘Maximum Concentration Values is for only impurities not included intentionally’ from
the last session of guidance is also deleted.
・The term ‘homogeneous’ is understood as “of uniform composition throughout”, so examples of
“homogeneous materials” would be individual types of plastics, ceramics, glass, metals, alloys, paper,
board, resins and coatings.
・ The term “mechanically disjointed” means that the materials can be, in principle, separated by
mechanical actions such as unscrewing, cutting, crushing, grinding and abrasive processes.
・A maximum concentration value of up to 0.1% by weight in homogeneous materials for lead,
mercury, hexavalent chromium, PBB, PBDE and of up to 0.01% by weight in homogenous materials for
cadmium will be permitted in the manufacture of new EEE.
Maximum Concentration Values
・A plastic cover would be a ‘homogeneous material’ if it consisted
exclusively of one type of plastic that was not coated with or had attached to
it any other kinds of materials. In this case, the maximum concentration
values of the RoHS Regulations would apply to the plastic.
・On the other hand, an electric cable that consisted of metal wires
surrounded by non-metallic insulation materials would be an example of
something that is not ‘homogeneous material’ because mechanical processes
could separate the different materials In this case the maximum concentration
values of the RoHS Regulations would apply to each of the separated
materials individually.
・A semi-conductor package would contain many homogeneous materials,
which include the plastic moulding material, the tin- electroplating coating on
the lead frame, the lead frame alloy and the gold-bonding wires.
＜The definitions and interpretations given in the above-mentioned are taken from the guidance
developed by the EC and agreed by TAC. It is dependent on the ratification of the
Commission’s draft Decision establishing the maximum concentration values.＞
WHAT IS HOMOGENOUS MATERIALS
lead-frame
coating
a
le
board
surface finish
d
m
f- ra
e
solder
copper board finish
epoxy
glass
copper
Figure – Soldertec (2005), cross section of Homogenous Materials
Outline of RoHS testing method by IEC
＜IEC62321＞－
recommendable analysis
Sample Pretreatment – From IEC Draft
－
Parts Which can be Measured Directly
Parts Recommended for Grinding
Or Else this have to be done
A sleeve without printing
A sleeve with printing
Metal case
Terminal Ａ
Resin
Insulation sealer
Terminal Ｂ
Sample pre-treatment can be very laboured intensive, grinding have been
recommended.
Pre-treatment is a must.
Well informed manufacturers will understand that we cannot measured directly the component without
sample pre-treatment. As can be seen, most electronic components are composite materials. The above
is taken from one of our customers who have been using our EDX for their checking.
Part sampling
grinding
test portion
Sample Size Classification - Extracted
from IEC draft
Coarse Grinding/Milling ≈ 1mm diameter (Conventional EDX
preferred , Micro beam result influence by local variation, Hand
held may not be sensitive enough)
Fine Grinding/Milling < 1mm daimeter (Conventional EDX
preferred , Micro beam result influence by local variation, Hand
held may not be sensitive enough)
Very Fine Grinding/Milling < 500um daimeter (Conventional
EDX preferred , micro beam result influence by local variation
but not so servere. Fine grinding take longer time and prone to
more contaimination from grinding. Hand held may not be
sensitive enough)
Conclusion 1
Beam size is not a very important factor to most manufacturer
because sample is extracted from supply chain management
rather than finished product which may have very small component.
Conventional EDX preferred – flexibility of 1, 3, 5 and 10mm
collimator.
Furthermore, grinding is recommended in such instances,
convenional EDX which have 10mm beam size would have bigger
sampling area than micro type having sampling area which can be
more than 100X smaller. Preferred –Conventional EDX (bigger
sampling area)
Therefore, the target would be going for better sensitivity, faster
analysis time and cost. Preferred – Conventional EDX (better
sensitivity, faster)
Detection Limit – From IEC Draft
Screening Limit and Implication on
Machine Performance
In ED-XRF detection limit is most often derived from the 3 sigma values.
⇒Eg. Detection limit for Cd is 20 ppm ⇒ P ≤(70-20)< X <(130+20) ≤ F
⇒I.e. Detection limit for Cd is 20 ppm ⇒ P ≤(50)< X <(150) ≤ F
⇒Grey Area is 50 to 150 ppm ⇒ 100ppm range
⇒Eg. Detection limit for Cd is 5 ppm⇒ P ≤(70-5)< X <(130+5) ≤ F
⇒I.e. Detection limit for Cd is 20 ppm ⇒ P ≤(65)< X <(135) ≤ F
⇒Grey Area is 65 to 135 ppm ⇒ 70 ppm range
⇒Eg. Detection limit for Cd is 35 ppm⇒ P ≤(70-35)< X <(130+35) ≤ F
⇒I.e. Detection limit for Cd is 35 ppm ⇒ P ≤(35)< X <(165) ≤ F
⇒Grey Area is 35 to 165 ppm ⇒ 130 ppm range
⇒Since detection limit is 35 ppm ⇒ anything less than 35 cannot be confirm with
certainty. (Hand held type in this area)
⇒ (35)< X <(165) ≤ F ⇒No confirmation possible, always in grey zone.
Detection Limit vs Analysis Time
An Instrument capable of 20 ppm detection limit at 100sec
would theoretically take 4 X more analysis time to cut it
detection limit by half (i.e 10 ppm = 400s ⇒ 5 ppm = 1600s)
Getting a machine with better detection limit not only give more
reliable result but also better time efficiency.
Conclusion 2
As far as possible, we should go for machine with
best sensitivity! Caused 3 sigma will vary with the
matrix of the unknown. Conventional EDX have
better detection limit if beam size is not an issue.
Time is also saved with better sensitivity machine
and more analysis throughput.
Preferred – Conventional EDX (better detection
limit)
Sampling Area – 1
Consider 2 beam size of 1mm and 10mm.
Area = π(1/2)2
Area = π(10/2)2
Area ratio = 1 : 100
Sample
= Hazardous
Substances
Sampling Area – 2
Measurement
Area
Beam spot
Measurement
Area
Beam spot
Measurement
Area
Beam spot
Measurement
Area
Beam spot
Reliability of data is a problem when measuring small inspection areas with a small measurement
diameter. The standard explanation, illustrated above, argues that a small measurement diameter
results in higher x-ray excitation efficiency because nearly 100% of the irradiation area provides
information from the measurement area and a larger measurement diameter results in lower x-ray
excitation efficiency because a large part of the radiation is lost. However, in actual analytical
environments workers often do not position the samples precisely, resulting in repeatability
problems. As shown above, precision and sensitivity can vary with micro x-ray fluorescence
systems, depending on how the measurement area is positioned. However, general purpose
systems are not vulnerable to this variability, allowing reliable measurements. Appropriate
corrections can be made to correct quantitation values for any variation in x-ray intensity due to
shifts in measurement position, but the quality and reliability of data will decrease significantly.
Conclusion 3
If we are grinding our sample, the best result
would come from a big x-ray beam rather than
from small spot. If size of x-ray is very much
smaller than the particle size, we may not detect
the elements even if it is present.
Preferred – Conventional EDX (Bigger sampling
area).
Summary
・IEC Testing method is based on 2 stages system such as screening by EDX
spectroscopy and precise quantitative analysis.
・XRF Analysis is an essential tool to screen out the hazardous substances.
・ Different types of ED-XRF are available in the market, care must be taken to
assess there suitability. Conventional type are by far the most cost effective and
time efficient.
・The testing method carrying out in Japanese set-makers can be mostly
applicable to IEC testing method though they maybe more stringent.
・ The standardization of RoHS testing method by IEC（ＴＣ－１１１：Ｗ
Ｇ－３） is not that of international green procurement but that of analytical
methods and sample pre-treatment.Therefore standardization of testing methods
is not directly correspond to the unification of procurement standards by
Japanese leading set-makers.
SPECTRA INTERFERENCE
Evaluating Spectra
In addition to elemental peaks, other peaks
appear in the spectra:
•
•
•
•
•
•
•
K & L Spectral Peaks
Rayleigh Scatter Peaks
Compton Scatter Peaks
Escape Peaks
Sum Peaks
Bremstrahlung
Diffraction Peak
K & L Spectral Lines
L beta
™ K - alpha lines: L shell e-
L alpha
K beta
K alpha
transition to fill vacancy in K
shell. Most frequent transition,
hence most intense peak.
™ K - beta lines: M shell etransitions to fill vacancy in K
shell.
™ L - alpha lines: M shell e-
K Shell
transition to fill vacancy in L
shell.
L Shell
M Shell
N Shell
™ L - beta lines: N shell etransition to fill vacancy in L
shell.
K & L Spectral Peaks From X-ray Tube
K-Lines
L-lines
Rh X-ray Tube
Scatter
Sample
Some of the source Xrays strike the sample
and are scattered back
at the detector.
Sometimes called
“backscatter”
Detector
Source
Rayleigh Scatter –Elastic Scatter
•
X-rays from the X-ray tube or
target strike atom without
promoting fluorescence.
•
Energy is not lost in collision. (EI =
EO)
They appear as a source peak in
spectra.
AKA - “Elastic” Scatter
EO
•
•
EI
Rh X-ray Tube
Compton Scatter –Inelastic Scatter
•
X-rays from the X-ray tube or
target strike atom without
promoting fluorescence.
•
Energy is lost in collision. (EI >
EO)
Compton scatter appears as a
source peak in spectra, slightly
less in energy than Rayleigh
Scatter.
AKA - “Inelastic” Scatter
•
•
EO
EI
Rh X-ray Tube
Sum Peaks
ƒ 2 photons strike the detector at the same
time.
ƒ The fluorescence is captured by the
detector, recognized as 1 photon twice its
normal energy.
ƒ A peak appears in spectra, at: 2 X
(Element keV).
BrKaSUM = 23.8kEV
BrKa = 11.9keV
Escape Peaks
•
•
11.9 –1.74 = 10.16keV
1.74 keV
Rh X-ray Tube
•
X-rays strike the sample and
promote elemental
fluorescence.
Some Si fluorescence at the
surface of the detector
escapes, and is not collected
by the detector.
The result is a peak that
appears in spectrum, at:
Element keV - Si keV (1.74
keV).
Brehmstrahlung
Brehmstrahlung (or Continuum) Radiation:
German for “breaking radiation”, noise that appears in
the spectra due to deceleration of electrons as they strike
the anode of the X-ray tube.
Brehmstralung Background
OVERLAPPING ELEMENTS –1
Cd – When Pb is present in large quantities (PbSUM)
PbLa – When As is present (AsKa)
– When Bi is present (BiLa)
Hg – When Ge is present (GeKa)
– When Zn is present in large quantities (ZnKb)
– When Br is present in large quantities (BrKaESC)
– When W is present (W Lb2)
OVERLAPPING ELEMENTS –2
BrKa – When Hg is present (HgLb1)
Cr – When Cl is present in large quantities (ClSUM)
– When Fe is present in large quantities (FeKbESC)
– When Ba is present (BaLb2,BaLg1)
– When V is present (V Kb)
– When Ni is present in large quantities (NiKaESC)
– When Co is present in large quantities (CoKaESC)
OVERLAPPING ELEMENTS –3
PbLb1 – When Bi is present (BiLb1)
– When Br is present (BrKb)
– When Se is present (SeKb)
– When Fe is present in large quantities (FeKaSUM)
BrKb – When Pb is present in large quantities (PbLb5)
– When Au is present in large quantities (AuLg1)
PROPOSED SOLUTIONS
1. KLM Markers
2. Primary Filters
3. Detectors Resolution
4. Sample Preparation
5. Other alternative Techniques ICP,
AA etc.
KLM Marker – Br
BrKa = 11.9keV
Relative Intensity ≈ 7 : 1
BrKb = 13.3keV
KLM Marker – Cr
CrKa = 5.41keV
Relative Intensity ≈ 7 : 1
CrKb = 5.94keV
KLM Marker – Hg
HgLb1 = 11.82keV
HgLa = 9.98keV
Relative Intensity ≈ 1 : 1
KLM Marker – Pb
PbLa = 10.56keV
PbLb1 = 12.62keV
Relative Intensity ≈ 1 : 1
KLM Marker – Cd
CdKa = 23.12keV
Relative Intensity ≈ 5 : 1
CdKb = 26.10keV
KLM Marker – Confirmation of Elements
Both PbLa and PbLb1 is present – confirmation of Pb
KLM Marker – Confirmation of Elements
PbLb1 is not present, hence Pb is not present.
KLM Marker – Confirmation of Elements
KLM Marker – Overlapping
KLM Marker – Overlapping(SUM Peak)
KLM Marker Checklist
1. Confirm the peaks position (Existence of Ka and Kb or La
and Lb1. Kb may not be visible if Ka is small in intensity)
2. Confirm the relative Intensity. (Ka is always greater than Kb,
La and Lb1 have about the same intensity).
3. Check for Known Interfering Peak. (Sum, Esc peak or other
K and L spectra)
Primary Filters
Primary Filters perform one of two functions
–Background Reduction and removal of interfering Peak
–Improved Fluorescence
Energy Dispersive X-ray Fluorescence
(EDX)
Sample
Primary
filter
Primary X-rays
Fluorescence X-rays
Multi Channel Analyzer
(MCA)
X-ray Tube
Solid State Detector
(SSD)
ＭＣＡ
Primary Filter – How it work
What is primary filter?
X-rays emitted from X-ray tube consist of the characteristic X-rays and
the continuous X-rays.
The continuous X-rays is part of the background (BG) component.
In case of the trace element analysis, the small fluorescence X-ray peak is difficult to
distinguish from the BG statistical error.
The primary filter effects the reduction of BG from X-ray tube and the improvement
of Signal / Noise (S/N) ratio.
Without primary filter
With primary filter
(1) Background Suppression
Blank PVC sample
at 50keV
Peak can be buried in the
Background and not detected.
Background without filter
Background with primary filter
(2) Improve Flourescence
Improve flourescence
PVC standard sample
With 28ppm of Cd
150s, 10mm collimator
(3) Interference Peak from X-ray Source
Remove RhKb Interference peak
PVC standard sample
With 28ppm of Cd
150s, 10mm collimator
(4) Identification of Elements
Removes characteristic X-rays from X-ray tube which can interfere with elemental
indentification
(5) Suppression of Sum Peak
Mo Filter MoNi Filter
Interfere with CdKa
(6) Confirmation of Diffraction Peak
Without Filter
With Filter
Comprehensive Filter Coverage
Without filter
Metal 1
Metal 2
Metal 3
Metal 4
Metal 5
Area of absorbed energy depends upon the material for
primary filter. Shimadzu EDX have 5 built in filters