Bresser National Geographic 40X-640X Instrucciones De Uso página 13

EN
6. Experiments
Now that you're familiar with your microscope's functions and how to prepare slides, you can complete
the following experiments and observe the results under your microscope.
6.1. Newspaper print
Objects:
1. A small piece of paper from a newspaper with parts of a picture and some letters
2. A similar piece of paper from an illustrated magazine:
Use your microscope at the lowest magnification and make a slide preparation from each object. Place
the slide with the newspaper on the microscope table and observe the slide. The letters in the newspa-
per appear broken because the newspaper is printed on raw, inferior paper. Now observe the slide with
the magazine preparation. Letters of the magazine appear smoother and more complete. The picture
from the newspaper consists of many small points, which appear somewhat dirty. The pixels (raster
points) of the magazine image appear sharper.
6.2. Textile fibres
Objects and accessories:
1. Threads of different textiles: Cotton, linen, wool, silk, Celanese, nylon and any others you can find.
2. Two needles:
Put each thread on a glass slide and fray each with the help of the two needles. Put a drop of water
over each thread with the pipette and cover each with a cover glass. Adjust the microscope to a low
magnification. Cotton fibres are of plant origin and look, under the microscope, like a flat, twisted band.
The fibres are thicker and rounder at the edges than in the centre. Cotton fibres consist primarily of
long, collapsed tubes. Linen fibres are also of plant origin; they are round and run in straight lines.
The fibres shine like silk and exhibit numerous swellings along the shaft of the fibre. Silk is of animal
origin and consists of solid fibres of smaller diameter than the hollow vegetable fibres. Each silk fibre
is smooth and even and has the appearance of a small glass rod. Wool fibres are also of animal origin;
the surface consists of overlapping scales, which appear broken and wavy. If possible, compare wool
fibres from different weaving mills, and note the differences in the appearance of the fibres. Experts
can determine the country of origin of wool based on its appearance under a microscope. Celanese
is artificially manufactured by a long chemical process. All Celanese fibres show hard, dark lines on a
smooth, shining surface. The fibres crinkle in the same way after drying. Observe the similarities and
differences between the different fibres.
Notes on Cleaning
• Before cleaning the device, disconnect it from the power supply by removing the plug or batteries.
• Only use a dry cloth to clean the exterior of the device. To avoid damaging the electronics, do not use
any cleaning fluid.
• Protect the device from dust and moisture.
• The batteries should be removed from the unit if it has not been used for a long time.
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