Copy of `HowMany - Unit Dictionar`

The wordlist doesn't exist anymore, or, the website doesn't exist anymore. On this page you can find a copy of the original information. The information may have been taken offline because it is outdated.


 HowMany - Unit Dictionar
Category: Mathematics and statistics > Dictionary of unit measurements
Date & country: 26/09/2008, USA
Words: 1293


right angle
a common unit of angle measure equal to 1/4 circle, 90°, 100 grads, or pi/2 radians.

ring
a traditional English unit of quantity for boards and staves, which were shipped encircled by metal rings. A ring equals 4 shocks, or 240 boards.

rms or RMS
an abbreviation for root mean square (see below), a mathematical technique for averaging the values of a changing quantity.

roede
a traditional Dutch unit of distance (see rood below), reinterpreted in 1820 as a metric unit equal to exactly 10 meters (32.8084 feet). The roede has also been used as a unit of area equal to one square (linear) roede; this is equal to 100 square meters or 1 are.

rope
another name for the rood , the distance unit.

round
the basic unit of time in boxing, equal to 3 minutes.

royal foot
the French pied de roi, also called the Paris foot in English.

rpm
a very common abbreviation for revolutions per minute (see above).

RSI or RSI
a symbol for the R-value of insulation when stated in SI units: square meter kelvins per watt (m2•K/W). RSI 1 is equivalent to R 5.678.

rundlet
a traditional measure of liquid volume, dating back to the Middle Ages. A rundlet is a small barrel usually holding 18 wine (U.S.) gallons (roughly 68.1 liters).

running foot
another name for a linear foot. Terms such as running meter and running yard are used similarly.

rute
a traditional German unit of distance corresponding to the English rod. In fact, 'rute' is the German word for rod. The rute had varying lengths, as short as 10 fuss (German feet) and as long as 16 fuss. This could be anywhere from about 3 meters to 4.5 meters.

rutherford (Rd)
a practical unit of radioactivity equal to the megabecquerel (MBq). This means 1 rutherford represents 1 million radioactive disintegrations per second. The unit is named for the New Zealand nuclear physicist Ernest Rutherford, later named Lord Rutherford (1871-1937), whose study of radioactivity led to the discovery in 1911 that most of the mass o...

rydberg
a former name for the kayser, the CGS unit of wave number. The name honored the Swedish physicist Johannes Rydberg (1854-1919).

sack
a traditional unit of weight, varying for different commodities shipped in sacks. In Britain, for example, the sack was a traditional measure for wool, fixed by Edward III at 364 pounds (26 stone) in 1340. In the U.S., a sack of salt is traditionally equal to 215 pounds, a sack of cotton 140 pounds, and a sack of flour 100 pounds. A sack of concret...

Saffir-Simpson category
a ranking of the strength of a hurricane, introduced by two American meteorologists and used by the U.S. National Weather Service to rank storms in the Atlantic and northeastern Pacific Oceans. A complete description, from the U.S. Atlantic Oceanographic and Meteorological Laboratory in Miami, is provided.

salmanazar
a large wine bottle holding about 9 liters, 12 times the volume of a regular bottle.

saltspoon (ssp)
a unit of volume formerly used in U.S. food recipes. The saltspoon equals 1/4 teaspoon or about 1.2 milliliters.

saros
a unit of time used in astronomy, mostly in predicting solar and lunar eclipses. The saros is equal to 6585.32 days (6585 days 7 hours 23 minutes), which is exactly 223 lunar months. (This is either 10 or 11 days more than 18 years, depending on the number of leap years during the period.) Astronomers in ancient times discovered that the saros is v...

saturation
a measure of the brightness of a color; see color units.

savart
a unit used in music to describe the ratio in frequency between notes. There are 301 (sometimes 300) savarts in an octave. This means two notes differ by one savart if the higher note has a frequency equal to 21/301 = 1.002 305 times the frequency of the lower note. The unit is named for a French physicist, Félix Savar...

scheffel or schepel
traditional units of dry volume. The German scheffel and Dutch schepel have both been redefined within the metric system, but in very different ways: the scheffel equals 50 liters (1.4189 U.S. bushels) and the schepel 10 liters (0.2838 U.S. bushels). Both words are usually translated 'bushel' in English, and both units were originally closer to the...

schock
a traditional German unit of quantity equal to 60. See shock below.

schooner
an informal unit of liquid volume. A schooner is a large tumbler or drinking glass holding about 400 milliliters or 13.5 U.S. fluid ounces. Similarly, in Queensland, New South Wales, and the Northern Territory (Australia) a schooner of beer holds 425 milliliters. In South Australia, however, a schooner is only 285 milliliters.

scim
see above under sccm.

Scots foot, Scots mile
traditional distance units in Scotland. The Scots foot equals 1.005 405 4 English foot (about 12.065 English inches or 30.645 centimeters). The Scots mile equals 320 falls or 5920 Scots feet, which is about 5952 English feet (1.127 English mile or 1814.2 meters). The English foot and statute mile, of course, are now official in Scotland.

Scoville unit
a unit measuring the concentration of capsaicin, the 'hot' ingredient in chile peppers. A measurement of, say, 50 000 Scoville units means that an extract from the pepper can be diluted 50 000 to 1 with sugared water and the 'burn' of the capsaicin will still be barely detectable by the human tongue. (In practice, the measurements are now made with...

se
a traditional Japanese unit of area equal to about 99 square meters or 118.4 square yards.

seah
an ancient Hebrew measure of both liquid and dry volume. The seah was equal to about 13.44 liters (about 3.55 U.S. liquid gallons or 2.96 British Imperial gallons).

season
a portion of a year. The word 'season,' derived from a Latin word meaning the time for sowing, originally meant one of the periods of the agricultural year. It has come to be used informally to mean the period of time characterized by any activity (such as the 'football season') or more specifically as a unit of time equal to 1/4 year. Ideas of wha...

second (" or s or sec)
a unit of longitude used in astronomy. Astronomers measure celestial longitude (or, as they call it, right ascension) in time units by dividing the equator into 24 hours instead of 360 degrees. This makes 1 second of longitude equal to 15 arcseconds.

second (" or sec)
a unit of viscosity defined by the time required for a specified amount of a liquid to flow through a particular viscometer. The Saybolt second (see above) was used in the U.S., the Redwood second in Britain, and the Engler degree in continental Europe.

second (s or sec)
a unit measuring the fuel efficiency of rocket engines. The measure is obtained as the thrust of the engine divided by the weight of fuel consumed per second (weight being measured at the earth's surface, or at 1 g). Since both thrust and weight are forces, their units cancel and the ratio is measured in seconds. This ratio is often called 'specifi...

second (s or ")
a unit of sidereal time in astronomy; see 'sidereal day' below.

second-foot
an informal name for the cubic foot per second as a flow rate for water.

SED
a symbol for standard erythemal dose, a unit used to measure the amount of skin-reddening ultraviolet radiation received by a person in the sun or in a tanning salon. One SED is equal to a dose of 100 joules per square meter (J/m2) of skin surface. The radiation producing skin reddening is confined to a narrow range of wavele...

seemeile
the German name for the nautical mile.

seer
a traditional unit of dry volume in northern India, equal to a little more than a liter. This is roughly the volume of a seer of grain.

Seidel
a traditional unit of liquid volume in Austria. The traditional Seidel was equal to about 354 milliliters; this is about 12.0 U.S. fluid ounces or about 12.5 British fluid ounces. In southern Germany the Seidel was larger, about 535 milliliters or 18.09 U.S. fluid ounces. Today a Seidel of beer in southern Germany and Austria is a small mug holding...

semester (sem)
an informal unit of time. The word semester comes from the Latin words for 'six months,' and originally a semester was understood to equal 6 months or 1/2 year. However, the word is now used chiefly to mean half the academic year at a school or college, a period of time which can vary from 15 to 21 weeks.

semester hour (sem hr)
a unit of academic credit, supposedly equal to one semester's study for a period of one hour per week. However, 'academic hours' slightly shorter than regular hours (often 50 or 55 minutes per class) are typically used in these calculations.

semibreve
a unit of relative time in music equal to 1 whole note or 1/2 breve.

semicircle
a unit of angle measurement equal to 1/2 circle, pi radians, or 180°.

semih
abbreviation for semihourly (every half hour) sometimes used in medical prescriptions.

semiquaver
a unit of relative time in music equal to 1/16 whole note or 1/32 breve.

sennight
an old English name for a week, formed as a contraction of seven nights. The word is pronounced like 'senate.'

septennium
a unit of time equal to 7 years.

septet
a unit of quantity equal to 7.

septuple, septuplet
a group of 7 items, especially 7 identical items; the word septuplet is also used for one member of the group.

ser
see seer (above).

sester
an old English unit of measure for honey. It seems to have been equal to about 2 U.S. gallons, 1.7 Imperial gallons, or 7.5 liters.

sestet
another name for a sextet, a unit of quantity equal to 6. This spelling is used in poetry to describe a six-line stanza and is sometimes used in music for an ensemble of 6 instruments.

seven
a unit of volume for beer in New South Wales and some other sections of Australia. A seven of beer is a glass holding 200 milliliters (about 7 imperial fluid ounces). This volume is called a butcher in South Australia and a glass many other parts of Australia.

sextet
a unit of quantity equal to 6.

sextuple, sextuplet
a group of 6 items, especially 6 identical items; the word sextuplet is also used for one member of the group.

SF
a common symbol for the square foot (ft2).

SFM
a traditional symbol for surface feet per minute, a unit measuring the rate at which a rotating tool, such as a lathe or saw, processes material. The term surface foot refers to the length of the material, similar to the linear foot.

SG
a common symbol for specific gravity, sometimes appended to a measurement as if it were a unit, as in '1.134 SG' for a specific gravity of 1.134. (Specific gravity is a mathematical ratio of masses, so it has no unit.)

shackle
a traditional unit of length used for measuring the lengths of nautical cables and chains, especially anchor chains. Anchor chains are formed by using shackles to join short lengths of chain. When the anchor is dropped and the chain runs out, a seaman counting the number of shackles can report the total length of chain deployed. The size of the uni...

shade number
a unit of light transmission for the protective glasses used in welding. If T is the fraction of visible light transmitted, the shade number is 1 + 7(-log10 T)/3. For example, if 1% of the light is transmitted, the shade number is 4.

shake
an informal unit of time equal to 10-8 second or 10 nanoseconds (ns). This unit originated in nuclear physics. In an atomic explosion, fast-moving neutrons break apart atoms of uranium or plutonium; the fission of these atoms releases additional neutrons which keep the reaction going. The shake is the approximate lifetime of ...

sheaf
a traditional measure for grain and various other commodities. A sheaf of grain is a bundle of stalks having a standard size, typically 30 to 36 inches (roughly 75-90 centimeters) in circumference. A sheaf of arrows is a bundle or quiver of 24.

shed
an exceptionally small unit of area used in particle physics. Like its big brother, the barn, the shed is used to express the apparent cross-sectional area of a particle from which other particles are scattered. One shed equals 10-24 barn, which is 10-52 square meter or 0.0001 square yoctometer (ym
sheng
a traditional unit of liquid volume in China. Like the Indian seer (see above), the sheng is a little more than a liter; 1.035 liter (1.094 U.S. quart) is one quoted equivalent.

shock or shook
a traditional measure of grain or straw. A shock of grain is usually 12 sheaves (see above), sometimes 10.

Shore hardness
a hardness measure determined by a Shore durometer. See duro.

short hundredweight
a common name for the U.S hundredweight or cental (100 pounds).

short ream
the traditional ream of 480 sheets of paper. The standard size for the ream has been increased in recent years to 500 sheets.

short ton (st or tn)
a common name for the U.S. ton (2000 pounds).

short ton unit (stu)
a unit of mass used in mining to measure the mass of the valuable metal in an ore. Customarily, the short ton unit is defined to be one U.S. ton of ore containing 1% metal, but it is the metal, not the ore, that is being measured. Thus the unit is really a unit of mass equal to 20 pounds (about 9.072 kilograms).

shortword
a unit of information equal to 2 bytes or 16 bits. See also word .

shot
another name for a shackle as unit of length for anchor chains. In this use, common in the U.S., a shot equals 15 fathoms, 90 feet or 27.432 meters.The origin of this name for a length of chain is not certain. It may be a corruption of 'shut,' since anchor chains are formed by shutting clasps or shackles to join shorter lengths of chain.

shovel
an informal unit of volume. In U.S. building trades, a common rule of thumb is that a cubic yard contains about 150 standard (no. 2) shovels of material. This means that a shovel contains about 5 liters and a cubic meter is about 200 shovels.

shower unit
a unit of distance used in studying cosmic radiation; it is the distance a charged particle travels in a given material while its energy decreases by 50%. Thus it depends on the material: in air the shower unit is very long, about 230 meters, but in water it is only 30 centimeters.

sidereal day
a unit of time used in astronomy, equal to the period of time in which the earth makes one rotation relative to the stars. If we could view the earth from outside the Solar System, we would see that it actually completes 366.242 rotations during one year (one revolution around the sun). We only count 365.242 because one rotation is cancelled out fo...

Siegbahn unit
another name for the X unit, a unit of distance used for describing the wavelength of x-rays. The name honors the Swedish physicist Karl M.G. Siegbahn (1886-1978), who received the Nobel Prize in Physics in 1924 for his work in x-ray spectroscopy.

sieve
a traditional measure of the fineness of a wire screen (such as the screening used in a sieve). Higher sieve numbers correspond to finer screens. In The U.S., 10 sieve fabric has openings of 2 millimeters; 100 sieve has openings of 0.15 millimeters. A similar but slightly different scale was used in Britain. In the metric system, sieve fineness is ...

sitio
a name used traditionally in Mexico and the southwestern U.S. for the square legua (see legua ), a unit of area equal to 25 million square varas or about 1800 hectares. The word means 'place.'

skein
a coil of yarn or cord. In retail trade, a skein is a highly variable unit, varying from one type of yarn to another and often from one manufacturer to another. In textile manufacturing, however, the skein is a unit of length equal to the lea.

skep, skæppe, skjeppe
a traditional unit of dry volume in northern Europe. Use of the unit was spread by Norse traders. In Britain, the skep was eventually identified with the bushel and the word survives as a name for a farm basket or a domed beehive. The Danish skæppe and Norwegian skjeppe are equal to 18 pots; this is equivalent to 17.407 liters (0.494 U.S. bus...

skock
a traditional Swedish unit of quantity equal to 60. See shock above.

skot
a unit of (low) luminance equal to 0.001 apostilb. This unit was used in Germany during World War II to describe permitted levels of lighting during air raids. One skot is the brightness of a surface produced by 1 nox or 0.001 lux of light. The name comes from the ancient Greek skotos, darkness.

slinch
a unit of mass invented by the U.S. National Aeronautics and Space Administration (NASA). The unit is part of a system based on the pound of force and the inch. One slinch is the mass accelerated at one inch per second per second by a force of one pound; thus the slinch equals exactly 12 slugs (see below) or about 386.088 pounds (175.1268 kilograms...

slm, slpm
symbols for standard liters per minute. 1 slm = 1000 sccm; see above under sccm.

smite
an old English word for a small amount of something; in recipes, a pinch. Originally the word probably meant one of the pieces into which something had been smashed.

smoz
symbol for the sailmaker ounce (see above).

snail
another name for a slinch (see above).

snit
a U.S. unit of volume for liquor equal to 2 jiggers, 3 U.S. fluid ounces, or 88.7 milliliters. The origin of this unit is unknown.

sol
a unit of time on Mars, equal to the average length of the Martian day as it would appear to an observer on the red planet. The sol equals 24 hours 39 minutes 35 seconds, which is 88 775 seconds or about 1.0275 Earth days.

solar neutrino unit (snu)
a unit used by astrophysicists to measure the rate at which neutrinos from the Sun are detected on Earth. Neutrinos are elementary particles with no charge and little or no mass (in 1999 it was reported that neutrinos do have a small mass). Scientists want to detect neutrinos because they carry crucial information about processes deep inside the Su...

spat
an informal unit of distance formerly used by astronomers. The spat is equal to the terameter (Tm, or 1012 meters). This is equivalent to about 6.6846 astronomical units. The origin of this usage is not clear; 'spat' may be an acronym for 'space unit' or 'space-time'.

SPF
abbreviation for 'sun protection factor,' a rating for lotions protecting against sunburn. The rating indicates how many times longer a person who uses the lotion can remain in the sun with an equivalent effect. For example, a person who would not sunburn in 10 minutes without protection can remain in the sun up to 150 minutes by using a lotion rat...

sphere
the traditional unit of solid angle measure, divided into 4(pi) steradians (see below). There are also 129 600/(pi) = 41 252.96 square degrees in a sphere. This unit is also called the spat (see above).

spherical degree
a unit of relative surface area for spheres, equal to 1/720 the total surface area or pi•R2/180, where R is the radius of the sphere. Thinking in terms of the Earth's surface, this is the area of the region in one hemisphere (northern or southern) bounded by the equator and two meridians of longitude one degree apart.

spin
a unit of angular momentum used in particle physics. The spin unit is equal to Planck's constant h divided by 2pi, or approximately 105.457 27 x 10-36 joule second (J•s). The spin of an elementary particle is always a simple multiple of this unit.

spindle
a traditional measure of length used for yarn. The length varied with the material; a spindle of cotton yarn, for example, was 15 120 yards (13.826 km), and a spindle of jute was 14 400 yards (13.167 km). The cotton spindle was also equal to 18 hanks.

splash
see dash .

split
a unit of volume for liquor equal to 4 jiggers, 6 U.S. fluid ounces, or 177.4 milliliters. The same name is used for a small wine bottle holding 1/4 the volume of a regular bottle; this would be about 187.5 milliliters. The unit appears to have originated as half the volume of a 12-ounce bottle of soda, which bartenders would split between two drin...

spoonful
an informal unit of volume, sometimes an alternate name for the teaspoon.

square chain (ch2 or sq ch)
a traditional unit of area in English surveying, defined to be the area of a square whose side equals Gunter's chain (4 rods or 22 yards). Thus the square chain equals 16 square rods, 484 square yards, 4356 square feet, or exactly 0.1 acre. In metric terms, the square chain equals about 4.0569 ares or 405.69 square meters.