MOOC: Instrumental analysis of cultural heritage objects

SELF TEST 2

When analysing the surface of a painting in a museum, which type of microscope would be more reasonable to use?

Single-lens microscope

Compound microscope

Why is glycerine used for fibre identification with optical microscope? (There can be one or more correct answers)

It makes the peculiarities of the fibre more visible

It loses the dust between fibres

Without glycerine it’s impossible to see fibres with microscope

A paint is examined first under light microscope and then under fluorescence microscope to find out whether zinc white and starch are in the paint’s composition. Which of the following statements is accurate? (There can be one or more correct answers)

Both fluorescence and in different wavelength ranges, i.e. with different colours, so that it’s easy to tell the difference.

Zinc white does not fluoresce, and therefore it is only possible to identify starch.

Neither of them has fluorescence, another method must be used to identify them.

Both fluorescence, but in the same wavelength range, i.e. with the same colour. So, it’s only possible to say that one or both are present but nothing else.

Which type of microscopy is described?

Is often used as an in situ method; its most important part is a set of lenses; samples can be analysed with transmitted light and reflected light; can be used for the analysis of the layered structure of the paint sample	Fluorescence microscopy Unselect Polarized light microscopy Unselect Light microscopy Unselect
High degree of sensitivity; can be used for quantitative and qualitative analysis; allows observing samples with optically anisotropic characters; paint components have different appearances	Fluorescence microscopy Unselect Polarized light microscopy Unselect Light microscopy Unselect
Needs excitation source and filters; is often integrated with other microscopes; is usually done in dark environment; can give preliminary information about dyes without sampling and extraction of dyes	Fluorescence microscopy Unselect Polarized light microscopy Unselect Light microscopy Unselect

Which of the following statements applies to which type of fibre?

It has a wide round-shaped cross-section and fibre surface, which looks like it’s covered with scales	Polyamide Unselect Linen Unselect Cotton Unselect Wool Unselect
It has a flat cross-section and apparent twist along with the fibre	Polyamide Unselect Linen Unselect Cotton Unselect Wool Unselect
It has nodes along with the fibre	Polyamide Unselect Linen Unselect Cotton Unselect Wool Unselect
It has a smoother surface, is shiny and resembles plastic wire	Polyamide Unselect Linen Unselect Cotton Unselect Wool Unselect