metric system For U.S. members, use metric terms only in situations where they are universally accepted forms of measurement (16 mm film) or where the metric distance is an important number in itself: He vowed to walk 100 kilometers (62 miles) in a week.
Sunday, June 20, 2010
Metrics in Stories - AP's Guideline
Normally, the equivalent should be in parentheses after the metric figure. A general statement, however, such as A kilometer equals about five-eighths of a mile, would be acceptable to avoid repeated use of parenthetical equivalents in a story that uses kilometers many times.
To avoid the need for long strings of figures, prefixes are added to the metric units to denote fractional elements or large multiples. The prefixes are: pico- (one-trillionth), nano- (one-billionth), micro- (one-millionth), milli- (one-thousandth), centi- (one-hundredth), deci- (one-tenth), deka- (10 units), hecto- (100 units), kilo- (1,000 units), mega- (1 million units), giga- (1 billion units), tera- (1 trillion units). Entries for each prefix show how to convert a unit preceded by the prefix to the basic unit.
In addition, separate entries for gram, meter, liter, Celsius and other frequently used metric units define them and give examples of how to convert them to equivalents in the terminology that has been used in the United States.
Similarly, entries for pound, inch, quart, Fahrenheit, etc., contain examples of how to convert these terms to metric forms.
ABBREVIATIONS: The abbreviation mm for millimeter is acceptable in references to film widths (8 mm film) and weapons (a 105 mm cannon). (Note space between numeral and abbreviation.)
The principal abbreviations, for reference in the event they are used by a source, are: g (gram), kg (kilogram), t (metric ton), m (meter), cm (centimeter), km (kilometer), mm (millimeter), L (liter, capital L to avoid confusion with the figure 1) and mL (milliliter).