12/10/96 Copyright Alan Shinn
A good first project is to look at the electron microscope specimen mounting grid that I have sent you. Be careful with the grid as it is extremely fragile and so light that if you breath on it, it will take flight - never to be seen again. Remove a piece of the bees wax that I included about 5mm in diameter. Warm the wax by kneading it between your fingers till it isÊsoft and sticky. Stick it onto the specimen pin (swivel the stage away from the lens as you do NOT want to get wax on that!!) and give it a bit of a wedge shape.
Place the grid just under the wedge and press down so it will stick (I use a piece of paper so the wax won't stick to the microscope). Turn the focus screw so the grid is about 1/2 mm higher than the lens and swivel it over the lens. Looking through from the other side, at a smallish light source like a 40 watt bulb at 5 feet (NOT a long fluorescent lamp) , turn the focus screw till the grid becomes sharp. This grid has 300 lines per inch so the holes are about .002 inch square.
An interesting way to estimate the power of the 'scope is to look at the magnified grid with one eye and to superimpose say a 1 inch object with the other eye by placing the object at the correct distance.
Measure the distance from the object to your eye. Divide the spacing of the lines on the grid into the size of the object --- 1"/.003333"=300 and multiply that by 10" divided by the distance to the object say (10"/16")*300=187.5 power.
Now you are ready to hunt for some "wee beasties". Cut a piece of the enclosed mica about 7mm (1/4") square and split it (peel it) into at least 4 thinner pieces. Using a hot needle or such, weld the mica onto your wedge of wax similar to mounting the grid. Place a drop of scummy pond water or such onto the side of the mica away from the lens and start hunting.
If you need to contact me:
Berkeley, CA 94703
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