SELF TEST 4.2

WD-XRF uses pulse-height discriminator to electronically classify the results; ED-XRF does not have an automatic classifier

ED-XRF uses pulse-height discriminator to electronically classify the results; WD-XRF does not have an automatic classifier

In WD-XRF, all the emitted fluorescence radiation reaches the detector at once; in ED-XRF, the detector detects all the fluorescent X-rays element by element

In ED-XRF, all the emitted fluorescence radiation reaches the detector at once; in WD-XRF, the detector detects all the fluorescent X-rays element by element

For the quantitative analysis, minimum of 1 g sample powder is needed

Can’t detect carbon in the sample

Impossible to analyse directly amorpheous materials

Can’t detect lighter elements than aluminium

Enables direct analysis from the object surface

Ground samples needed for quantitative analysis

Easy to use

Computer-aided material identification

A cross-section of the paint sample can be analysed

Non-destructive

No sample preparation needed

Cost-effective

Mineralogy effects are eliminated

The particle size effects are eliminated

Less material is needed for sample preparation

The method is relatively easy

It is possible to identify all the inorganic and organic materials

It is possible to determine which crystalline phases are in a mixture

Interpretation of XRD diffractogram is easier compared to the interpretation of WD-XRF spectrum

For the interpretation, library of known crystalline structures is used

It is possible to determine if amorphous material is present in the mixture

Analysis of XRD patterns is complicated and is typically done by a specialist

 … determining bond types in the samples

… quantitative analysis and for that only 1 mg of sample is needed

… measuring diffraction angles and the intensities of diffraction peaks

 … measuring crystalline structure of the sample

Cellulose-based fibres in the textiles

Crystalline pigments in the paints

Amorphous pigments in the papers

Binders in the paints

Resins in the varnishes

Minerals in the clays

No sample preparation

Large database of known crystalline structures

Fast elemental analysis

Elemental mapping possibility

Possibility to perform accurate quantitative analysis

Cost-effective

Computer-aided material identification

Possibility to perform in-situ analyses

XRD can be used to identify crystalline materials

XRF can be used to determine the structure of crystalline materials

XRD and XRF can be used to identify liquid materials

XRD can be used to identify amorphous materials

XRF can be used to determine elemental composition of the sample

XRD can be used to determine elemental composition of the sample