The exception is Celsius, which is always capitalized. It employs a decimal system that is both logical and easy to use. Although a USP drop is 0.05 mL, some nurses use the minim symbol (m) as an abbreviation for drop. In the United Kingdom, Canada, and some other commonwealth countries, the British Imperial system of mass is still sometimes used. The avoirdupois system is categorized into 7 subdivisions: Dram. vitamin A carotenoids. These lists and other useful information on SI can be found in the book Guide to the Use of the Metric System [SI Version], which is available from the U.S. There should always be a space between the numeric digits of a quantity and its SI symbol (e.g., “5 g” rather than “5g”). (1) Metric unit names (such as gram, meter, kelvin) are not capitalized (unless, of course, the name is at the beginning of a sentence), even though some units, such as the basic unit kelvin and derived units such as the newton (for force) and the pascal (for pressure), are named for persons. At one time, it was common practice for physicians and nurses to use apothecaries’ fluid volume symbols as “abbreviations” for common measurements when writing the directions-foruse portion of a prescription or medication order. The basic units of mass for the avoirdupois system are the grain, the ounce, and the pound. The liter is the fundamental unit of volume used in pharmacy and medicine; it is essentially the volume of 1,000 cubic centimeters (cm3). Metric Association maintains an Internet site that contains information on correct usage of the SI-metric system; their Guide to the Use of the Metric System [SI Version] has even more complete information (4,5). The avoirdupois system is the common or customary system of weights used in commerce and households in the United States. See Tables 7.5 and 7.7 for apothecaries’ equivalents and conversion factors. In older scientific literature, you may see the unit of length, the angstrom, which uses the symbol Å; 1 Å = 10−10 m. 5. The avoirdupois pound contains 7,000 grains, or 256 drams of Using the average of 50 mg/drop, and the density of water of 1 g/mL, this would give 20 drops/mL or 0.05 mL/drop. c. Even more hazardous was the use of the apothecary ounce symbol (3) as an abbreviation for 30 mL or two tablespoonfuls, and the apothecary symbol for one-half ounce (3ss) as an abbreviation for 15 mL or 1 tablespoonful. Start studying Avoirdupois System - Pharmacy Compounding. c. The symbols are never followed by periods unless a symbol is at the end of a sentence. and text used on the RF Cafe website are hereby acknowledged. The SI or metric system is now the only system of measurement acceptable for use in pharmacy and medicine, but since both the apothecaries’ and avoirdupois systems (sometimes called the common or customary systems) are used both in commerce and daily life activities, pharmacists and pharmacy technicians must be knowledgeable about all three systems. It was adopted as a legal system (although not a mandatory one) in the United States in 1866. b. 1. Intersystem Conversion for Weights and Volumes, Temperature Conversions and Calculation of Mean Kinetic Temperature. See Tables 7.5 and 7.7 for the various units of measurement and equivalents. a. The basic unit of volume in SI is the cubic meter (m3), but the liter (L), although not an SI unit, is approved for use in SI for measuring liquid volume. The original basic units of the metric system were the meter for length and the kilogram for mass. The lowercase g without a period is the only acceptable symbol for gram. The Avoirdupois System originates from France and is commonly used today in the United States to describe units of weight. Standards were desired that were based on unchanging physical characteristics of specified elements. 4. At this time, rapid scientific and industrial development was taking place, and it became apparent that a standardized, internationally recognized system of measurement was needed. In this case, pharmacists and physicians have mistakenly used or interpreted the (3) symbol as an abbreviation for 1 tablespoonful, giving a dose that was either one-half or double that which was intended. The U.S. Some of the basic rules are listed here, and the correct format for some of the symbols commonly used in pharmacy and medicine are listed in Table 7.3 (4,5). a. The units of mass for the apothecaries’ system are the grain, the scruple, the dram (formerly spelled drachm), the ounce, and the pound. In 1960, the metric system was refined and the International System of Units (SI) was adopted. f. As noted earlier in the example of milli (m) and mega (M), letter case is important. The letter “p” is not to be used for the word per, but per may be written out (e.g., 5 milligrams per milliliter). Dial-up modems blazed along at 14.4 kbps c. The British Imperial system of volume uses the same unit names, but these represent different quantities. Mugs, Cups, Ball Caps, Mouse Pads, Vitamin A, 1 i.u. For many years, the reference standard for the meter was a platinum–iridium bar with etch marks delineating a meter; a 1-kg platinum–iridium block was used as the standard for mass. d. Symbols are always written in singular form but, when the word for a unit is used, the plural form is used when appropriate. b. The avoirdupois grain has the same mass as the apothecaries’ system grain (see section C, Apothecaries’ System), but both the ounce and the pound are different in the two systems. In 1875, the United States joined 20 other countries in signing the Treaty of the Meter, which adopted the metric system and established the International Bureau of Weights and Measures to work internationally to advance and maintain the system (1,2). while typing up your telephone line, and a nice lady's voice announced "You've Got We still measure and give our body weight in terms of pounds, buy butter and meat by the pound and pasta and cereal by the ounce, and have postage for letters and packages calculated based on ounces and pounds.