(3) Keep your balance clean at all times. Remove any spilled drug or
chemical immediately with a soft brush or clean dry towel.
(4) Never weigh materials directly on the pans. Always protect the pans
with powder papers or weighing boats. Corrosive substances should be weighed in
properly tared, stoppered bottles.
(5) Support the beam with the securing device at all times, except when
checking equilibrium, or making a weight determination. This will protect the delicate
mechanism from needless wear that leads to inaccuracy. Assure that the pans are
supported when adding weights or substances to the pan.
(6) Always keep your weights covered in their proper containers, except
during actual use.
Handle weights with forceps only.
(8) Check the weights three times; once, when you remove them from their
box and place them onto the pan; again, while they are in use; and finally, when you
return them to their box. Form this habit early in your career to avoid serious errors in
weighing which can have a disastrous effect on the health and lives of your patients, as
well as on your career.
(9) Finally, be as meticulous and accurate in preparing the medication, as
you would have another pharmacy specialist be in preparing medication for you.
To measure liquids, you generally measure their volume. Volume is space and
so you measure the space they occupy. Customarily, we refer to solids by their weight
and to liquids by their volume, but there are a few exceptions to this rule. Glycerin,
acids, and many other liquids are received by weight, but are dispensed by volume.
a. Equipment Used to Measure Volume. Liquids are measured most
frequently in graduates. Occasionally, for greater accuracy, pipettes, burettes, and
volumetric flasks may be used. Graduates are of two types: (1) the graduated cylinder,
and (2) the conical or pharmaceutical graduate. Both types are available in many sizes
and are calibrated in units of volume. Those that are calibrated by hand are more
accurate than the machine-marked variety.
(1) Graduated cylinder. The graduated cylinder, calibrated only in milliliters,
is widely accepted as the most accurate graduate. It is not practical for general use
because it is difficult to clean, dry, fill, and empty.