You don’t have to be a scientist or medical professional to use a metallographic microscope.  If you’re a hobbyist or an amateur scientist, there is no reason why you shouldn’t be able to use this instrument efficiently, considering that current designs and features on metallographic microscopes make them easy to set up and use.

Metallographic microscopes are the most commonly used tools in the study of organic matter such as rocks, minerals and metals.  They are also used for the quality control inspection of semiconductor products.  Because of their versatility, metallographic microscopes are used in a variety of applications and industries.  Now that metallurgy is becoming an increasingly popular science, more and more instruments are being designed to make them easy to use.  Here are steps on how to setup and use a metallographic microscope:

Determine the type of metallographic microscope you are using.
There are two types of metallographic microscopes.  One is the upright type and the other is the inverted type.  The upright type is more commonly used than the inverted type.  The upright type has a similar design to the conventional microscope, allowing specimens to be viewed mounted on a stage with the objective lens pointing directly downward.  This is the ideal microscope to use with small sized and flat specimens, or those placed on glass slides.

The inverted metallographic microscope, on the other hand, has objectives pointing upward, allowing a bigger working distance between the specimen and the objective lens.  Because the working distance is greater, larger specimens may be observed.

Prepare the specimen.
In metallurgical studies, the specimens are often opaque or solid materials.  To observe them effectively, samples must be taken for microscopic examination.  When preparing the specimen, there are several considerations – the size, material and orientation of the sample.  This will allow you to obtain the best sample possible from the source material.  If necessary, some specimens such as rock and mineral samples have to be polished and etched with diluting acids.  These acids are used to enhance the sample’s grain structure, whether it’s metal or alloy.  When grain boundaries react with the acids, the surface is etched, producing a 2-D image of the grain structure.

In some cases thin, polished slices of the specimen may be produced, provided you have the necessary tools to perform the job.  This thin slice allows the observer to view the tiny structures that make up the rest of the sample.  Once this has been done, mount the specimen on the mechanical stage using the spring caliper and make sure to lock it in place.

View the specimen.
Begin by adjusting the illumination.  Metallographic microscopes often use electric light sources, allowing you to adjust the intensity depending on what you want to view.  It is also good to remember that metallographic microscopes use different types of illumination technologies, including dark field microscopy, transmitted light microscopy, incident bright field microscopy and polarized light microscopy, among others.  The light source in metallographic microscopes is quite powerful and should offer sufficient illumination.  Otherwise, you can rely on the built in LED light source.

Decide on which filter to use.  There are three colored filters used with metallographic microscopes.  These are green, blue and yellow.  These filters have different uses, depending on the material and what you wish to view.

Next, set the magnification.  Begin with the lowest magnification and lowest objective lens first.  If the magnification is insufficient, begin increasing the magnification and adjust the objective lens.  The optical system in metallographic microscope have lenses that range from a low 100x to a high of 1000x while the objectives begin at 10x and have a high of 100x.  Use the focusing mechanism to produce a sharper image.  Use the coarse focusing knob first, especially if you’re using low magnification power.  Use the fine focusing knob at higher magnifications.  Another effective way of viewing specimens is to use immersion fluid on the specimen.  This is effective in eliminating air between the specimen and the objective lens and reduces the refraction of light.  The result is higher resolution.

Using microscope accessories for image capture and storage
The metallographic microscope can be mounted with accessories to extend their functionality.  These accessories are used to capture and store images viewed through the instrument.  These include video capture, digital camera systems and computers.  A digital and video capture camera system designed specifically for use with a microscope will allow you to take pictures of the image.  If the camera allows storage of the image, you can also keep the images as electronic files.  With a computer, images taken with a metallographic microscope can be efficiently stored, sent as e-mail attachments and viewed through a computer monitor.

When using metallographic microscopes with attachments, make sure you understand how these accessories are mounted and used.  Metallographic microscopes are easy to use, even by beginners.  What makes them more complicated are the addition of accessories.