ARL QUANTRIS Top performance CCD based metals analyzer ILAP Meeting P. Dalager / E. Muller.

ARL QUANTRIS Top performance CCD based metals analyzer ILAP Meeting P. Dalager / E. Muller

2 Outline Introduction Market requirements What is the ARL QUANTRIS? Instrument description Software Analytical performance Customer benefits Conclusions

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

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

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

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

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

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

9 Instrument description Optics: Flat field Detector Grating Primary slit

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

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

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

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

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

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)

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

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

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

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

20 Hardware description Optical system Spectrometer views

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)

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

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 !

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

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

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

27 Analytical development Numerical Processing Filtering Typical improvements due to smoothing filters SD calculated on 10 runs performed on SUS RE12

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

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

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

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

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

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

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 )

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 )

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 )

39 Analytical Performance Fe base: reproducibility Excellent element More limited element

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

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)

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

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 )

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 )

45 Analytical Performance Al base: reproducibility example (1 ) Majors (> 500 ppm) in SUS vs. datasheet ARL 3460

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

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

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

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

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

ARL QUANTRIS Top performance CCD based metals analyzer ILAP Meeting P. Dalager / E. Muller.

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Transcript of ARL QUANTRIS Top performance CCD based metals analyzer ILAP Meeting P. Dalager / E. Muller.