Why PEAXACT?
Unsure whether PEAXACT should be your future software tool for quantitative spectroscopy? This article lists typical questions and answers, grouped by topics.
Uniqueness
PEAXACT is not just another software for arbitrary multivariate process data. PEAXACT is designed and optimized for spectroscopy, meaning that we treat a spectrum as what it is – an array of coherent intensity values, to which nature has given a characteristic appearance like peaks, bands, landscapes, etc. Why should we blow up this structure into pieces by treating it like any generic set of multivariate process data?
PEAXACT extends the toolbox for spectral analysis with the so-called Spectral Hard Modeling methods.
Obviously, the first choice for spectral analysis should always be a univariate approach, e.g., Peak Integration. Unfortunately, it regularly fails due to signal overlap, and in this situation, Spectral Hard Modeling allows us to resolve the overlapping ranges by fitting pre-defined peaks. Since these peaks have been obtained from the pure component spectra, their intensity is directly correlated to their concentration!
The good thing is that a Hard Model can be made as flexible as required, e.g., in case of shifting peaks, shape changes, etc. Once the shape of the mixture spectrum is correctly captured by the Hard Model, the quantification is independent of these changes! The performance of such a Hard Model can easily be assessed by the spectral fit error: does the model properly fit to the spectrum, and if not – where and why?
Versatility
Obviously, the spectrum has to be peak-shaped to apply a peak-based model. But this is true for many spectroscopic techniques, including Raman, mid-infrared, or NMR spectroscopy – even GCs! And if model-driven methods like Peak Integration or Spectral Hard Modeling fail, you can still apply data-driven methods like Partial Least Squares (PLS) in PEAXACT.
Sure. Complex spectra with myriads of peaks need careful handling. But anyway, you are free and encouraged to reduce the spectral ranges that you use for the analysis – reducing the number of peaks, reducing complexity, enhancing reliability. We have a case where we don’t use more than a 200 cm-1 window for a full analysis of 6+ components with a Hard Model!
For process applications, the essential performance indication is how accurate a newly acquired spectrum – which is unknown to the model – can be predicted. This is reflected in the RMSE (root mean squared error) of the model validation, ideally the RMSEP from a test-set validation – the situation closest to the prediction of unknowns. Most other performance indicators, like R², RMSE of calibration, or even RMSE from a cross-validation are easily greenwashed by overfitting!
Unlike statistical methods, Hard Models (and other mechanistic models) bring trust and reliability in process applications since they are structured by physical laws – a benefit that easily overcompensates for small lacks of accuracy.
We all know that there will never be a comprehensive list of methods. But, from our 15-years experience in process spectroscopy, we also know that the absolute majority – certainly more than 95% – of applications in automated, unsupervised process analysis is using one out of these three methods. And by the way, PEAXACT also provides classification methods!
Usability
PEAXACT is already an essential part of PAT toolboxes in major PAT groups in the (petro-)chemical and pharmaceutical industry, in research institutes and universities, and in SMEs. PEAXACT users appreciate that the software provides all relevant methods for spectral analysis, powerful visualization tools, and excellent support of the modeling and analysis workflow. In the end, PEAXACT is the only tool that is at the same time:
- independent of equipment manufacturers;
- streamlined to spectra, not to generic multivariate data;
- has the widest variety of spectra-specific analysis methods – while not confusing you with super-expert settings.
No surprise that manufacturers like Endress+Hauser (formerly Kaiser Optical Systems), Tornado Spectral Systems, or tec5 will recommend PEAXACT for their spectroscopic devices!
Remember that a commercial software like PEAXACT comes with professional maintenance and documented upgrades, unit testing, communication interfaces, etc. You can rely on industry-proven quality standards and make sure you efficiently use your time for the analysis of spectra, not for debugging your private code.
By the way: Even our most "curious" customers will confirm that we are efficiently supporting your custom tools in PEAXACT environments, even considering to integrate them into our own future development!
Absolutely not! Custom results allow you to define mathematical expressions for whatever post-processing you need, including conditional expressions (IF ... THEN). This boosts your flexibility significantly!
Interoperability
PEAXACT is a process software meant to run 24/7 without supervision or manual interaction. Running PEAXACT models from a measurement software or as a part of an automated monitoring system is pretty easy through our predictors. You will find that several manufacturers of equipment or software have seamlessly integrated PEAXACT into their products as a third-party predictor. In other cases, you might want to implement the AppServer in a custom environment or use ProcessLink as a standalone predictor with an integrated automation interface. Our Product Finder guides you through the selection!
Nothing easier than that. ProcessLink is our stand-alone predictor based on folder monitoring, which can sit on top of any spectra-generating device. It helps to turn every spectroscopic instrument into a process analyzer since it comes with a built-in OPC-UA server!
Training, Service, Support
Don’t be afraid. Of course, learning a new tool always takes more effort than using the one you've gotten used to already – but it will pay off! Through our blog we provide tutorials and useful tips, but the best is always to have personal contact with the support people! We invite you to do so.
We can schedule a web demo to let you start with PEAXACT, but the most popular way to implement PEAXACT as a tool is our two-day on-site training for you and your PAT group. Most of the time will be spent in practical exercise, meaning that you have two supervised days of learning how to operate PEAXACT. Be sure that on day 3, you will be able to create models on your own!
We are at your side to support your modeling at any time. Please contact us so we can arrange a remote support session for your specific problem!
If you rather feel like giving away the modeling task to us, we will be happy to take that over. Depending on the size of your modeling project, we will offer you one of our Analyzer Apps, allowing you to start right through with a validated analysis model!