Spectroscopy and Chemometrics News Weekly #47, 2015

Near Infrared

NIR-Sensor ermittelt Trockensubstanz während der Mischwagenbefüllung | Futterkomponente LINK

Ultra-low maintenance FTNIR analyzer for the refining & petrochemical industries | pauto LINK


Seeing Through Crude Oil for Efficient Oil Separations using Short-Wave Infrared (SWIR) Cameras – AZoSensors LINK


RoboBees Can Fly and Swim. What’s Next? Laser Vision – Smithsonian UAS UAV LINK


Scientists create an all-organic UV on-chip spectrometer – The U.S. Department of Energy’s Ames LINK


… detection of contaminants in agro-food products, … melamine levels in milk using vibrational spectroscopy LINK


Examining Pigmented Human Tissue using SWIR Raman Spectroscopy – AZoSensors LINK


SCiO Molecular Scanner UNBOXING – Video LINK


Dear NIR-Spectrometer vendors, this is about how you can improve customer web-traffic | NIRS Spectrometer LINK

Efficient development of new quantitative prediction equations for multivariate NIR spectra | spectra LINK

How to Develop Chemometric Near-Infrared Spectroscopy Calibrations in the 21st Century? | NIR LINK

How to Develop Near-Infrared Spectroscopy Application Today? | pharma lab analysis chemist TechTrends LINK

Improve chemical analysis accuracy by optimized chemometric models for Near-Infra-Red (NIR) Spectroscopy LINK

Improving Accuracy, Precision and Robustness of NIR-analysis LINK

NewsLetter: Spectroscopy and Chemometrics News Weekly 46, 2015 | Molecular Spectroscopy NIRS Chemometrics Raman LINK

Pro Tip: The NIR calibration is the central key to accurate NIR measurement LINK

Services for professional Development of Near-Infrared Spectroscopy Calibration Methods | NIR Quality Testing LINK

Procedures for NIR calibration – Creation of NIRS spectroscopy calibration curves

Do you know the effect that you prefer to try out their favorite data pretreatments in combination and often try the same wavelength selections based spectra of the visualized?

You try as six to ten combinations until one of them selects his favorite calibration model, to then continue to optimize. Since then suddenly fall to outliers, because it goes in depth, so is familiar with the data, we know now the spectra of numbers of outliers and is familiar with the extreme values.

Now, the focus is on the major components (principal components, Latent Variables, factors) and makes sure not to over-fit and under-fit not to. The whole takes a few hours and finally one is content with the model found.

So what would happen if you all in the beginning tried variants found outliers removed and re-evaluated and compared? The results would be better than that of the previous model choice? One does not try out? Because it is cumbersome and takes hours again?

We have developed a software which simplifies this so that also the number of model variations can be increased as desired. The variants generation is automated with an intelligent control system, as well as the optimization and comparing the models and finally the final selection of the best calibration model.

Our software includes all the usual known data pretreatment methods (data pre-processing) and can combine them useful. Since many Preteatments are directly dependent on the wavelength selection, such as the normalization the determined within a wavelength range of the scaling factors to normalize the spectra so that pretreatments with the wavelength ranges may be combined. So a variety of settings sensible model comes together that are all calculated and optimized. For the automatic selection of the relevant wavelength ranges, different methods are used, which are based on the spectral intensities. Thus, for example, regions with total absorption is not used, and often interfering water bands removed or retained.

Over all the calculated model variations as a summary outlier analysis can be made. Are there any new outliers (hidden outlier) discovered, all previous models can be automatically recalculated, optimized and compared without these outliers.

From this great number of calculated models with the statistical quality reviews (prediction performance) the optimum calibration can now be selected. For this purpose, not simply sorting by the prediction error (prediction error, SEP RMSEP) or the coefficient of determination (coefficient of determination r2), but by several statistical and test values are used jointly toward the final assessment of optimal calibration.

Thus we have created a platform that allows the highly automated work what a man can never do with a commercial software.

We therefore offer the largest number of matched to your application problem modeling calculations and choose the best calibration for you!

This means that our results are faster, more accurate, robust and objective basis (person independent) and quite easy for you to apply.

You have the full control of the models supplied by us, because we provide a clearly structured and detailed blueprint of the complete calibration, with all settings and parameters, with all necessary statistical characteristics and graphics.

Using this blueprint, you can adjust the quantitative calibration model itself in the software you use, understand and compare. You have everything under control form model creation, model validation and model refinement.

Your privacy is very important to us. The NIR data that you briefly provide us for the custom calibration development will remain of course your property. Your NIR data will be deleted after the job with us.

Interested, then do not hesitate to contact us.

NIR Spectroscopy Calibration Report for quantitative predictive models

When you send your quantitative NIR spectra data to our NIR Calibration Model Service, you get a detailed calibration report (calibration protocol) of the found optimal calibration settings, so you are able to see all insights and easily re-build the model in your NIR/Chemometric software.

Here is a part of our calibration report, that exactly describes the data used in the calibration set (CSet), the validation set (VSet) and the test set (TSet). The numbers are the number ids of the spectra in your delivered NIR data file.

The calibration method settings and parameters are
Waveselection : the variable selection or wavenumber selection or wavelength selection
Pretreatments : the spectral data pre-processing
PCs : the number of  Principal Components (PC) or Latent Variables (LV)
Method : the modeling method algorithm used, e.g. PLS

Then the statistical analysis of the PLS model by the different sets (CSet, VSet, Tset).

Calibration Report

Statistical analysis of calibration, validation and test results : 1 Name, 2 Unit, 3 N : number of spectra, 4 N : number of samples, 5 Average spectra count per sample, 6 Reference values, 7 Min, 8 Mean, 9 Median, 10 Max, 11 Standard deviation, 12 Skewness : left (-) or right (+) lack of symmetry, 13 Kurtosis : flat (-) or peaked (+) shape, 14 Model statistics, 15 RPD, 16 R², 17 RMSEC, RMSEP, RMSET : root mean square of prediction errors, 18 SEC, SEP, SET : standard error (bias corrected), 19 Bias, 20 Skewness of prediction errors, 21 Kurtosis of prediction errors, 22 Intercept, 23 Slope, 24 Intercept (reverse), 25 Slope (reverse), 26 Sample Prediction Repeatability Error, 27 Sample Prediction Repeatability Error (of Missing data MSet)

This shows how we deliver the optimal settings. With the statistical values, the NIR model predicted values of all spectra and additional plots you are able to compare with your re-built model to verify that the models perform nearly equally.


It is easy
1. send your NIR data (we do not collect, share or sell your data)
2. receive your optimal model blueprint
3. build it, validate it, use it

We have a Chemometric software not to do chemometrics,
we have the solution to build an optimal model for your data
so you can get better NIR measurement results.

So we don’t name it a “Chemometric Software”.
It’s a service named, as that what it delivers, a Calibration Model.
It gives you an optimal chemometric model for your NIR data.
That is what you want to achieve.

So don’t bother about Chemometrics and endless helpless possibilities
and spend your time with clicking and waiting for a chemometric software,
when you can get an optimal model for your data as a service!

There is no lock-in.
Because there is no software to install.

There is no black-box.
Because the model is delivered as a detailed and complete blueprint in human readable form.

You stay independent.
Because you can always choose:
- You can still do it as you have done it before.
- You will experience that with the service you will get the better models faster and is inexpensive.

Let’s have a try
please contact us, so we can help you!

NIR Calibration Modeling (Part 2)

( to part 1 )

All the below categories are implemented by using multiple different algorithms and formulas which leads to many different calibrations.

Steps in modeling
  • Data Cleaning – (bad data, missing values, duplicate elimination, spectral quality / intensity / noise, input value typing errors, …)
  • Initial Calibration set up – selection of calibration, validation and test samples
  • Wavelengths selection
  • Data preprocessing, pretreatments
  • Method calculation
  • Choosing the number of Principal Components / Latent Variables
  • Validation of calibration model / Statistics of performance – (accuracy, precision, linearity, repeatability, range, distribution, robustness / stability, sensitivity, simplicity, etc.)
  • Outlier examination and removal

The problem of choosing the optimal number of factors to find the optimum between underfitting and overfitting is solved by having multiple methods and protocols implemented leading to multiple calibrations.

The evaluation and the selection of the best calibration is based on many individual statistical values including the most popular RMSEP, SEP, Bias, SEC, R2 and PCs etc.

Results and Reporting

A detailed calibration report is provided detailing the best available calibration containing all calibration parameter settings and statistics of prediction performance of the calibration set, the validation set and the test set. A visual expression of the calibration is provided with the most importance plots.

Our service works with any quantitative NIR spectra data set in the standard JCAMP-DX format and uses mainly PLS and PCR to be compatible with other chemometric calibration software.


The NIR Calibration service offers the following benefit: Saving money
  • Improving the accuracy and reliability of already used NIR calibration models have high potential in various manufacturing processes as well as in quality assurance.
  • increased accuracy of analysis => better control of the production process => optimum process flow => better quality => less waste => more throughput.
  • quick and inexpensive to create professional NIR calibration models.
  • relief of their own staff
Time savings
  • for data cleaning (increasing data quality) – missing data, outlier search, wrong data (conflicting information), outlier removal
  • for the search for the optimal NIR model parameter settings (calibration set, wavelength selection, data pretreatments, factor selection)
  • for the calculation of different variations of the model
  • for the validation, evaluation and selection of the optimal model (error, SEP, RMSEP, RMSEC, RPD, fit, R2, bias, slope, …)
  • time-consuming calculation of huge calibration models
  • no long trial and error and waiting in the used NIR software until the calibrations seems to work
NIR analytical accuracy
  • higher reliability due to accuracy and robustness of NIR calibration models
  • the possibility of comparison with your own created or already existing or purchased NIR calibrations
  • what performance increase of analytical accuracy is possible
  • improvement of robustness with respect to change of the product matrix and possible instruments drift
Professional NIR calibration models
  • decades of experience in chemometrics for NIR spectroscopy
  • based on theoretical and applied good practice and know-how
  • application of various guidelines and rules
  • application of vendor-independent NIR chemometric software
  • outsourcing of NIR calibration method development and calibration equation maintenance
  • improving the robustness of NIR prediction model
  • avoid traps and pitfalls of the complicated chemometrics
Detailed results
  • The service provides optimal calibration settings for your NIR data.
  • You get full insight into the NIR calibration, as it is produced and detailed statistical values as a performance index assisted with graphics.

NIR Calibration Service

Services and software for data analysis and analytical modeling for spectroscopy.

This NIR calibration service provides the custom development of optimal quantitative NIR calibration models based on your collected NIR and reference data for vendor independent full range NIR spectrometer analyzers (NIR = Near Infra Red spectroscopy) based on chemometric multivariate methods like Partial Least Square Regression (PLS, PLSR) and Principal Component Regression (PCR).

The key points

The NIR calibration model is decisive for the analysis accuracy.

NIR analysis results make the difference.

Near-Infrared Data Modeling Calibration Service

The problems

Imagine how many publications and literature of NIR spectroscopy (JNIRS) and chemometrics (Journal of Chemometrics) is present.

Did you find the time for the right to designate to read, to study, to incorporate them into practice? Do you have all this knowledge at your calibration developments always present, that you consider anything important, the statistical results, interpret them correctly, analyze the graphs accurately and apply all the tips & tricks of optimizing correctly?

We have the solution for you!

We’ll help you to create and optimize your calibrations. You retain complete control. You have your calibration, with our help, himself under control.

You can view the complete calibration of all the settings down to the smallest detail precisely documented and visualized.

You can also make any changes in the settings. This means you remain independent and have the control in your hand.

We will help you for the time-consuming and knowledge-intensive part. You get the best calibration solution and decide for yourself

Try it and see for yourself