CLINICAL LAB SCIENEC

CHAPTER 9: LABORATORY MATHEMATICS 211
A
B
FIGURE 9-2 (A) Compact portable electronic scale. (B) Cabinet balance.
Source: Delmar/Cengage Learning.
common in medical facilities as it prevents confusions with times that are a.m. and
p.m. Midnight is 0000 hours, noon is 1200 hours, and afternoon and evening hours
are added to 12 (noon). Thus, 1:00 a.m. is 0100 hours, and 1:00 p.m. is 1300 hours
under the 24-hour system.
Useful Metric Terms
The metric system uses decimal notations in increments of 10. Units that are
smaller than the three basic units may be obtained by dividing by increments
of 10, or multiplying by a power of 10. As an example, the prefix kilo refers
to “1,000,” so a kiloliter would be 1,000 L. Other useful prefixes are shown
in Table 9-1. Table 9-2 shows conversions in size by use of scientific notation,
which helps to avoid using numbers with many zeros.
Converting Units of Measurement
Converting One Metric Unit to Another
When performing laboratory determinations, it is often necessary to convert from one
metric unit to another. If one knows the equivalents, it is quite simple, much more
Table 9-2 Scientific Notations (Units Increased or Decreased by Powers)
This table shows the consistent gains and decreases in size or number, as the prefi xes change in
relation to the scientific notations.
10 n Prefix Decimal 10 n Prefix Decimal
10 –12 pico .000000000001 10 12 tera 1,000,000,000,000
10 –9 nano .000000001 10 9 giga 1,000,000,000
10 –6 micro .000001 10 6 mega 1,000,000
10 –3 milli .001 10 3 kilo 1,000
10 –2 centi .01 10 2 hecto 100
10 –1 deci .1 10 1 deca 10
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