Because of the bewildering variety of abbreviations for scientific and technological terms and the inconsistency of treatment, writers and editors are advised to consult with publications like The Chicago Manual of Style or a handbook specific to a scientific discipline or to an industry to confirm standard modes of abbreviation for specific terms. This post provides an assortment of examples that demonstrate the seemingly chaotic nature of scientific and technological abbreviation.
Abbreviations for scientific and technological terms generally do not use periods; an exception is physical dimensions for nonmetric quantities such as gr. for grain, qt. for quart, and bbl. for barrel and temporal abbreviations such as sec. (second), hr. (hour), and mo. (month). Note, too, that unlike abbreviations for physical dimensions, those for durations of time include an s when they are plural: “15 mins.,” “5 yrs.,” etc.).
Abbreviations of metric units are almost invariably lowercased; an exception is mL for milliliter, so that a lowercase l is not confused for the numeral 1. The format of abbreviation of US units of measure is inconsistent. Sometimes, abbreviations may consist of the first two letters of a word (for example, mi. for mile); in other cases, the abbreviation may be formed from the first and last letters (as in yd. for yard). Rarely, an abbreviation of a foreign term is used, as with lb. instead of po. or pd. for pound, while the abbreviation oz. for ounce is based on the medieval Italian form onza.
Just as these abbreviations are usually appropriate only for charts and tables, not for what is called running text (the prevailing content in a publication distinct from display copy—headlines, captions, and the like—and graphic elements such as charts and tables), symbols are usually avoided in running text, but the percentage symbol (%) is occasionally used there, especially in statistically dense content, as are symbols for minutes and seconds in time or distance. However, these should be style as primes (′) and double primes (″), although some publications use straight, or dumb, quotation marks (‘ or “) or even curly, or smart, ones (’ or ”).
Capitalization of scientific and technological terms is variable, sometimes even for terms in the same category. Just as the first letter for the abbreviation of tablespoon is capitalized to distinguish Tbsp. from the abbreviation for teaspoon (tsp.), Bps (for “bytes per second”) and bps (for “bits per second”) are distinguished by initial capitalization of the former but not the latter, and abbreviation of megabit and megabyte are distinguished as Mb and MB, though kilobit is abbreviated kb, while kilobyte is shortened to KB (or simply K). The first letter of the abbreviations for “kilobyte per second” (Kbps) and “megabyte per second” (Mbps) is also capitalized.
Abbreviations of scientific units named for scientists have initial capitalization, though the spelled-out terms themselves are lowercased—for example, Bq (becquerel), Da (dalton), and J (joule). This is true of abbreviations of words based on surnames, such as F for farad (an abbreviation of Faraday) and V for volt (from Volta). And because the -bel in decibel is in honor of Alexander Graham Bell, that segment of the word for a unit of measurement of sound is capitalized in abbreviation to dB. Likewise, the first letter in Btu is capitalized because it stands for British. (The other letters stand for thermal and units.)