Agriculture Reference
In-Depth Information
Analytical balance
Analytical balance is used to measure mass to a very high degree of
precision and accuracy. The measuring pan(s) of a high precision (0.1 mg
or better) analytical balance is inside a transparent enclosure with doors so
as to avoid dust particles and airflow in affecting the balance's operation.
Analytical precision is achieved by maintaining a constant load on the
balance beam, by subtracting mass on the same side of the beam to which
the sample is added.
Precaution should be taken to avoid air flow during recording of weights
and under dust-free condition
Compound
microscope
Microscope is a tool used to view small tiny elements, which are mostly not
clearly visible by the naked eye. In life science, medical science, and other
branches, microscope is an essential instrument in research. As light from a
source passes through the object, the lens nearest the object, the objective
lens, produces an enlarged image of the object in the primary image angle.
The lens that you look into, the eyepiece, acts as a magnifier and produces
an enlarged image of the image produced by the objective lens. The
magnification is the product of the eyepiece magnification by the
magnification of the objective lens, usually 4
,10
,40
, and 100
. For
example, a 10
eyepiece in conjunction with a 40
objective will give you
a magnification factor of 400; that means the object will be magnified 400
times larger than you can view it with the naked eye. Viruses, molecules,
and atoms are beyond the capabilities of today's compound microscopes
and can be viewed only with an electron microscope. Always use
immersion oil while viewing any object using 100
eyepiece to prevent
the damage of the lens. Wipe off the lens gently with tissue paper soaked in
xylene to remove the oil after use. Never use a dry cloth or paper towel to
wipe any optical surface as you could scratch a lens. Use an air blower or a
camel hair brush to whisk away dust. If there is dirt on the eyepiece that
can't be removed with air or the brush, gently wipe it with a piece of clean
cotton
