ARL QUANTRIS Top performance CCD based metals analyzer ILAP Meeting P. Dalager / E. Muller
Transcript
Slide 1
ARL QUANTRIS Top performance CCD based metals analyzer ILAP
Meeting P. Dalager / E. Muller
Slide 2
2 Outline Introduction Market requirements What is the ARL
QUANTRIS? Instrument description Software Analytical performance
Customer benefits Conclusions
Slide 3
3 Introduction CCD based instruments appeared nearly a decade
ago New technology permitted lower cost, smaller bench-top
instruments and flexibility Potential to analyse all elements
without any optical compromise As long as wavelengths required
covered and resolution good enough Compromises were needed to
integrate technology, resulted in Smaller spectrometers with
limited resolution Key elements not measurable (N) High detection
limits, making analysis of minor elements not possible at levels
required by specifications and norms (C, P) RSD of minor elements
(5-10 %) too limited to comply with norms RSD of major elements
(< 2 %) too limited to optimize usage of alloying elements and
save production costs Stability frequently too limited to provide
accurate results day by day
Slide 4
4 Introduction Thermo (formerly ARL, then Thermo ARL) Decades
of experience in providing OE spectrometers Instruments with
superior analytical performance, stability, reliability and
lifetime ARL METALS ANALYZER, ARL 3460, ARL 4460 Thermo has
experience with first generation of OE solid state detectors based
instruments ONESPARK (CID) ARL EASYTEST and ARL ASSURE (CCD) Thermo
took challenge to break most compromises overcome limits
experienced really achieve performance of traditional PMT based
instruments
Slide 5
5 Market requirements Solid state detector based OES with
analytical figures of merit comparable to PMT instruments Analyze
CNOPS elements in steel and P in Al High reliability, stability and
availability Flexible instruments with no hardware modifications
required for calibration extensions at customer sites Unlimited
lines selection for multi-base applications Black-box operation
with easy-to-use instrument and software
Slide 6
6 What is the ARL QUANTRIS ? Second generation OE-CCD
spectrometer Based on up to three spectrographs and solid state
detectors Utilizes high end linear CCDs Utilizes high end CCS
source First CCD based instrument with analytical performance
equivalent to traditional PMT based instruments able to analyse
elements C, N, P, S accurately even at lowest concentrations
Slide 7
7 Outline Introduction Market requirements What is the ARL
QUANTRIS? Instrument description Choice of technical solutions
Spectrometer optics Solid state imagers Excitation source
Instrument stability Hardware description Analytical development
Software Analytical performance Customer benefits Conclusions
Slide 8
8 Choice of technical solution Spectrometer optics Three
alternatives investigated Paschen-Runge with chained linear solid
state detectors along Rowland circle Echelle with 2D solid-state
detectors Flat-field with linear solid-state detectors
Slide 9
9 Instrument description Optics: Flat field Detector Grating
Primary slit
Slide 10
10 Instrument description Optics: Flat field Advantages Simple
configuration Simple detection system Simple mapping procedure
(calibration, drift correction) Simplicity of configuration
facilitates manufacturing of stable and reliable instruments
Numerous manufacturers of linear detectors Difficulties Fields not
flat over long distances Linear CCDs not arbitrary long Compromise
spectral range/ resolution Narrow slits for good resolution Reduced
light flux Limited dynamic range High light flux for good dynamic
range Broader slits needed Lower resolution Works only in 1. order
of diffraction Resolution limited for some critical
wavelengths
Slide 11
11 Choice of technical solution Optics: ARL QUANTRIS Up to
three flat field spectrographs Separation of spectral range to be
analyzed within 3 modules 129-200 nm (N, C, P, S) 200-410 nm
410-780 nm (Na, Li, K ) Optimized light collection in each module
through specific lenses and gratings Direct reading for all 3
modules to avoid fibre optics No aging of fibres and no replacement
necessary
Slide 12
12 Choice of technical solution Solid state imagers
Multi-parameter evaluation of CMOS and CCD techniques CMOS
Technology of choice for high- volume, space-constrained
applications where image quality requirements low Security cameras
PC videoconferencing Automotive in-vehicle uses... CCD Most
suitable technology for high- end imaging applications Digital
photography High-performance industrial imaging Most scientific and
medical applications
Slide 13
13 Choice of technical solution Detector: ARL QUANTRIS CCD
Specifically designed for high end industrial, scientific or
military applications Color RGB CCDs used in monochromatic mode
Increases signal/noise ratio Open new possibilities for increased
dynamic range Lumogen coating for CCDs used in VUV spectrograph to
improve quantum efficiency Reduced quantum efficiency at lower
wavelengths Coatings mandatory to increase quantum efficiency below
200 nm Not coated CCD detector
Slide 14
14 Choice of technical solution Source: ARL QUANTRIS Two types
of sources utilized on PMT instruments HIREP on ARL METALS ANALYZER
and ARL 3460 Current follows natural decay imposed by RLC circuit 8
different excitation conditions available Patented Current
Controlled Source (CCS) on ARL 4460 The only servo-controlled
digital source on market Solid state electronics High degree of
flexibility in selection of peak current, frequency and current
waveforms Enables optimization of all figures of merit for each
metal Achieves best accuracy, sensitivity and reproducibility
Compact design close to spark stand in a Faraday cage Suppresses RF
leakage and improves general stability
Slide 15
15 Choice of technical solution Source: Our solution ARL
QUANTRIS optics with limited resolution in comparison to
Paschen-Runge optics with 1 m focal length CCS source best tool to
compensate limitations and achieve best results CCS source selected
Current [A] Time [s] Plateau (any form: 256 points) Peak (30-250
A)
Slide 16
16 Long-term stability of utmost importance in harsh
environments to ensure quality analytical data Key influence on
precision, accuracy and speed of analysis Time spent in drift
correction is time lost Drift corrections are expensive Frequent
drift correction can contribute to errors Metals production depends
on stable analytical instruments to ensure the process is under
control First generation of CCD based instruments dont have best
stability reputation Exception being ARL ASSURE thanks to flat
field architecture Thermo established reputation with stable
instruments Company knowledge exploited to provide stable
instruments Choice of technical solution Stability
Slide 17
17 Easier to achieve stability with simple flat field
architecture Well proven cast iron spectrometer Provides unrivaled
stability both on short and long term Spectrometer running under
vacuum Provides rigidity Independant from atmospheric pressure
variations Thermo-controlled CCDs to 0.5C at 0.5-2C Achieves low
noise in addition to stability Water-cooled stand Automatic optical
alignment and spectrum profiling on each CCD Choice of technical
solution Stability
Slide 18
18 Hardware description Stand Stand main features With 3
optical channels Argon flow optimized by computer simulation Casted
analysis table for light passes, argon admission and exhaust
optimization Quick analysis table exchange Indirect water cooling
table Very low stand-by flow Fast flush and dust blow out system
Use of short pulsed argon jets Allow to reduce argon flush time
even with Nitrogen analysis Keep the spark chamber free of extra
dust over extended time Consequently reduces maintenance frequency
and down time
Slide 19
19 Hardware description Optical system main features
Spectrometer in cast iron, under dry vacuum 3 spectrographs with
flat field diffraction system Focal length:200 mm Primary slit
width:15 m Holographic aberration corrected concave gratings VUV
spectrograph:3240 gr/mm (at grating center) Basic spectrograph:1105
gr/mm (at grating center) Optional alkaline spectrograph:590 gr/mm
(at grating center) Average dispersion: VUV spectrograph:1.2 nm/mm
Basic spectrograph:3.5 nm/mm Optional alkaline spectrograph:6.7
nm/mm Average bandpass per pixel : VUV spectrograph:8 pm/pixel
Basic spectrograph:24 pm/pixel Optional alkaline spectrograph:43
pm/pixel
Slide 20
20 Hardware description Optical system Spectrometer views
Slide 21
21 Analytical development Analytical conditions (2) Fe base
Standard timings and source parameters CCD and acquisition
parameters * Adjusted to obtain max. intensity on IS lines (needs
number of integrations to be adapted) Analysis time Fe base 31s
(computation time added) Al base 29 s (computation time added)
Slide 22
22 Analytical development Preliminary Manipulation of Spectral
Data After summation of intensities of elementary integration
times: 3 spectra obtained for each CCD line (RGB) Added to obtain 1
spectrum for each CCD with up to 3 x better S/N Pixel intensities
of all CCDs used for computations (next slides) Pixel intensities
of all CCDs also stored in a file allowing graphical display of the
spectra With header with various information With polynomial
coefficients and pixel intensities for each CCD Coefficients make
spectra in nm from different instruments comparable
Slide 23
23 Analytical development Numerical Processing - Generalities
Weaker performance of CCDs vs. PMTs Sensitivity typically 2-3
orders of magnitude lower Lower precision Numerical processing
offers unique differentiators to the ARL QUANTRIS Because spectrum
available and almost no limitation on line selection Drawbacks
partly compensated by "massaging" spectra with Drift correction at
each acquisition Processing windows with full flexibility Various
filtering modes Various intensity modes Various background
subtraction modes Use of best internal standard for each analyte
line Deconvolution Enormous potential, at every level !
Slide 24
24 Analytical development Numerical Processing For drift
correction Drift correction Drifts unavoidable ! For each CCD, at
each acquisition Well defined and resolved lines compared to a "
mask " Set of reference lines Drift correction algorithm " moves
and deforms " spectrum in order to find the smallest difference
with reference lines Special algorithms to find accurate maxima
positions of measured lines Parameters similar to and for
restandardization
Slide 25
25 Analytical development Numerical Processing Processing
window Chosen to eliminate interferences as much as possible Chosen
to solve desperate situations Can be shrunk to a line amplitude
measurement Shoulder
Slide 26
26 Analytical development Numerical Processing Filtering
Smoothing filters matched to line characteristics Improve pixel
reproducibility Reduce noise Improve reproducibility of integration
Raw run 1 Raw run 2 Low-pass Filter
Slide 27
27 Analytical development Numerical Processing Filtering
Typical improvements due to smoothing filters SD calculated on 10
runs performed on SUS RE12
Slide 28
28 Analytical development Numerical Processing Background
Subtraction Various modes Off-Peak ( = Bg ) On-peak If off-line
background signal not available Rectangular or trapezoidal None
Quality of background on- peak not always sufficient If good
background improves sensitivity, bad background can degrade
reproducibility Bg
Slide 29
29 Outline Introduction Market requirements What is the ARL
QUANTRIS? Instrument description Software Analytical performance
Customer benefits Conclusions
Slide 30
30 Software WinOE the powerful assistant First Windows based
version launched 1991 Regular releases (13) to add functions,
improve ease-of-use, support new OS Current version 3.1 Runs on all
Thermos PMT based instruments Runs on Windows 2000 Most powerful
package on market Most robust package on market Simplest to use
package on market
Slide 31
31 Software New WinOE 3.2 Main novelty: supports ARL QUANTRIS
now! Line library manager Libraries managed per matrix Graphical
tool to display the spectra acquired from the 3 CCD's and identity
unknown peaks
Slide 32
32 Software New WinOE 3.2: Lines library manager Lines
libraries organized per base: Fe, Al, Cu A base lines library
includes selected spectral lines, spectrum processing algorithms
and information Lines libraries available separately Multi-base
capability New elements added without hardware change Easy addition
in analytical programs of any line included within the installed
lines libraries Lines of other bases need corresponding
library
Slide 33
33 Software New WinOE 3.2: Qualitative analysis Spectra display
function, dedicated to the display of analysis spectra On-line and
off-line view Spectra manipulation tools Peak search function Also
called finger print mode Permits qualitative analysis of any
element in wavelength library > 146000 lines Perfect tool for
metallurgical research User friendly thanks to a modern look 'n
feel Evolving functionality Nice tool for metallurgical
research
Slide 34
34 Outline Introduction Market requirements What is the ARL
QUANTRIS? Instrument description Software Analytical performance
Customer benefits Conclusions
Slide 35
35 Analytical Performance New detection limit definition
Traditional DL calculation method DL = 3 * relative * BEC relative
relative standard deviation stored for the pure matrix sample with
10 runs With background subtraction, too easy to artificially show
very low DLs Alternative method had to be defined DL
=t*s*Sensitivity t : Extracted from Student table for p =99.5 % (3
s) and df=9 t = 3.2498 s : standard deviation in intensity measured
on pure sample Sensitivity : slope of calibration curve at zero
concentration (C 1 - C o /(I 1 -I o ) Definition already used by
some customers Most accurate method Gives very similar results on
PMT based instruments with definition above
Slide 36
36 Key elements: Steel: C, N, P, S, Pb, Si, Mn Cast iron : Pb,
Mg, La, CeN Garanteed values at Thermo Calculation according to
norms Not every competitor calculated according to norms ARL
QUANTRIS in steel 4 x inferior to ARL 3460 C better 5 x better than
ARL ASSURE ARL QUANTRIS in cast iron Equivalent to 3460 Analytical
Performance Fe base: detection limits (3 )
Slide 37
37 Low alloy steel 10 runs per sample Key elements Minor : C,
N, P, S, Pb, Si, Mn Major : Co, Cr, Ni, Mn, Mo, W ARL QUANTRIS 15 %
< ARL 3460 4 x better than ARL ASSURE Analytical Performance Fe
base: reproducibility example (1 )
Slide 38
38 Cast iron Sample CKD 248 10 runs per sample Key elements
Minor : Pb, Mg, La, Ce Major : C, Cr, Ni, Mo ARL QUANTRIS 50 %
better than ARL 3460 7 x better than ARL ASSURE RSD major elements
C, Ni: > ARL 3460 Cr, Mo: < ARL 3460 RSD trace elements Pb: =
ARL 3460 Analytical Performance Fe base: reproducibility example (1
)
Slide 39
39 Analytical Performance Fe base: reproducibility Excellent
element More limited element
Slide 40
40 Calibration curves examples Excellent linearity Reduced
absorption effects Excellent Standard Errors of Estimate (SEE)
Analytical Performance Fe base: accuracy C in cast ironCr in cast
iron
Slide 41
41 Cr-Ni calibration Same ranges and samples on both
instruments Key elements Minor : C, N, P, Pb, S Major : Co, Cr, Ni,
Mn, Mo, W Residual errors, QUANTRIS Better on key elements Cr, Mn
Analytical Performance Fe base: accuracy (SEE)
Slide 42
42 Analytical Performance Fe base: stability Stability of
utmost importance when performing routine analyses With vacuum
spectrometer, automatic optical alignment and spectrum profiling,
demonstrates exceptional stability Reduces need for drift
correction and allows more time for production sample analyses
Examples show long-term stability of elements N in a low alloy
steel and Mg in a cast iron over 7 days without any intermediate
drift correction Standard deviation achieved remains in range of 2x
precision
Slide 43
43 Typical values yet Application still in development
Guaranteed values to be slightly higher Key elements: As, Ca, Cd,
Li, Na, P, Pb, Sb, Sn ARL QUANTRIS in Al 10 x inferior to ARL 3460
Analytical Performance Al base: detection limits (3 )
Slide 44
44 Al-Si-Cu sample 10 runs per sample ARL QUANTRIS Clearly
better on major elements Sometimes inferior on minor elements
Analytical Performance Al base: reproducibility example (1 )
Slide 45
45 Analytical Performance Al base: reproducibility example (1 )
Majors (> 500 ppm) in SUS vs. datasheet ARL 3460
Slide 46
46 Outline Introduction Market requirements What is the ARL
QUANTRIS? Instrument description Software Analytical performance
Customer benefits Conclusions
Slide 47
47 Customer benefits Stability Feature Instrument virtually
drift free Simple flat field architecture Well proven cast iron
spectrometer running under vacuum Thermo-controlled CCDs to 0.5 C
at 5C Water-cooled stand Automatic optical alignment and spectrum
profiling on each spectrograph Benefit Instrument delivers
dependable performance 24 x 7 x 365 Minimizes drift correction
procedures and keeps instrument available for its primary task
Analysis of unknown samples Minimizes consumption of expensive
drift correction samples
Slide 48
48 Features and benefits Reproducibility Feature Instrument
divided in 3 spectrographs Thermally controlled CCDs for low noise
Optimal analytical line for each matrix and even each quality
Optimal Internal Standard, optimized for each analytical line
Optimal data treatment for each line (smoothing, filtering,
background substraction) Digital source with optimum waveform for
each matrix Benefit Confidence in reproducibility of results
delivered Precision of minor elements (RSD 1-5 %) enough to comply
with specifications and norms Precision of major elements (RSD
0.2-1 %) permits minimal usage of alloying elements and save
production costs
Slide 49
49 Features and benefits Flexibility Feature Full spectrum
available with no spectral line compromize Wavelength coverage from
129 nm to 780 nm Extension of analytical needs with no hardware
modifications In some cases spectrograph 410-780 nm could be
requested Fast change tables and electrodes for multi-matrix
applications Benefit All elements requested by the metals industry
can be analyzed Easy identification of unknown elements Low
investment costs Up-grades performed with minimal downtime Easier
operation in multi-matrix applications Lowest operating costs
Slide 50
50 Outline Introduction Market requirements What is the ARL
QUANTRIS? Instrument description Software Analytical performance
Customer benefits Conclusions
Slide 51
51 Conclusions Thermo not first with CCD-based OE spectrometers
But when we do it, we do it right !! For first time CCD based
spectrometer with true performance of PMT based instruments All
spectral lines for all metals types Full and continuous wavelength
coverage from 129-870 nm For the first time low C, N analysable
with CCD-based instrument Detection limits, reproducibility,
accuracy, stability, reliability Rugged construction to be used in
hostile environments Stability to minimize drift corrections
Automatic optical alignment and spectrum profiling
Slide 52
52 Conclusions Perfect instrument for metals producers and
transformers Lower operating costs, flexibility for identification
of unknown elements Perfect instrument for industrial central
laboratories, analytical services contract laboratories
Multi-matrix applications without any compromizes Permits also
lowest costs of ownership Price difference rapidly offset by
savings on costs of ownership Easily up-gradable at lower
costs