Optimized Algorithms for True Standardless Quant

Standardless quantification analysis is one of the most important requirements in SEM labs around the world. Today, EDAX offers the most finely tuned algorithms of any EDS manufacturer for doing True Standardless Quantitation, with error levels nearly equivalent to standards-based methods. There are many significant reasons for the superior results SEM-Quant offers:

• Improved Algorithms
• No Reliance on Beam Stability
• No Calibration for Quantification
• No Reliance on Special Libraries
• Partial Standards Flexibility
• Accurate results under the widest variety of conditions

EDAX recently developed the most significant breakthrough in standardless quantification analysis. In the past, Pure Element Intensity Factors (PEIF's) were used as correction factors in the quantification algorithms. These PEIF's were measured and not independent of kV; therefore several sets existed for different working kV's. By modifying the equations that calculated the Pure Element Intensities, EDAX was able to make them more accurate and actually eliminate the measured PEIF's. This eliminated the need for different sets of PEIF's at different kV's.

Another significant benefit of EDAX's new algorithms is that it's finally possible to do accurate and reliable light element quantitative analysis. The following data were acquired over a wide range if excitation conditions to illustrate the quality of the EDAX standardless quantitative method. Note the calculated results show a very small deviation from the given results.

With a PEIF or "virtual standards" approaches, any differences in beam current conditions between the unknown and a standard must be factored into the calculations or errors will be introduced in the results. (This is one reason some systems require calibration every few hours. Beam stability can also be an issue with older SEMs - one of the reasons EDAX is a preferred choice for upgrading older systems.)

EDAX's SEM-Quant alogorithm is totally independent of beam current. Reliance on a fluctuating parameter is eliminated. The examples here also show quant results at several different voltages, indiacting the robust nature of EDAX's algorithms.

No Calibration for Quantification

With SEM-Quant there's no need to revisit a calibration standard every few hours. Calibration for the purposes of correcting the calculation for beam current has never been required with the SEM-Quant standardless method. The only calibration required is for spectral channel alignment, and this calibration is typically carried out a few times a year.

No Reliance on Spectral Libraries

When stored spectra are used for the purposes of standardless quantification, errors are introduced from comparing data obtained from standards at one particular time, with data from an unknown at another particular time. All differences in accelerating voltage, beam current, SEM column geometry, and specimen preparation introduce errors which must be corrected for in the software with further assumptions. Since SEM-Quant does not use a spectra library, more accurate results can be obtained with any SEM, at all operating conditions.

Partial Standards Flexibility

For those users who prefer to use standards, SEM-Quant still offers the flexibility to do full and partial standards. EDAX is confident though that after you see the quantification results obtained from our new eDX- ZAF algorithms, you'll be a believer in True Standardless Analysis!

Accurate results under the widest variety of conditions

Only EDAX offers a complete range of true-standardless quantification routines that provide full flexibility at any SEM working conditions, while maintaining superior accuracy and reliability.

An SEM operator often works with a wide variety of different parameters including accelerating voltage, beam current, aperture settings, and working distance to name a few. Being limited to specific conditions for quantification (kV or beam current for instance) reduces throughput, and often limits the ability to maximize the SEM imaging capabilities.

EDAX true-standardless quantitative routines offer the ability to do analysis at the widest range of SEM conditions. Accurate and reliable results can be obtained at different accelerating voltages, beam currents, and various time constants.

None of the EDAX true-standardless quantification packages rely on beam stability. Better accuracy is therefore offered despite fluctuations in beam current due to changing parameters, and/or an aging filament. There is also no reliance on a spectral library which can limit the conditions at which an operator can perform quantitative analysis.

Today, EDAX offers three algorithms for the SEM Quant standardless analysis: ZAF, PhiRhoZ and its exclusive Phi-ZAF. Tables 2 and 3 further illustrate the superior performance over a wide range of accelerating voltages, utilizing either L or K line when necessary, on difficult samples containing both heavy and light elements.Put the flexibility and power of EDAX SEM Quant true-standardless quantification to work for you. Rely on EDAX SEM Quant analysis to provide accurate and reliable results that you can trust.