A 6 μm diameter carbon filament above a 50 μm diameter human hair
|1 μm in ...||... is equal to ...|
|SI units||1×10−6 m|
|Natural units|| 6.1877×1028 ℓP |
|imperial/US units|| 3.2808×10−6 ft |
The micrometre (international spelling as used by the International Bureau of Weights and Measures; 1×10−6 metre (SI standard prefix "micro-" = 10−6); that is, one millionth of a metre (or one thousandth of a millimetre, 0.001 mm, or about 0.000039 inch).SI symbol: μm) or micrometer (American spelling), also commonly known by the previous name micron, is an SI derived unit of length equalling
The micrometre is a common unit of measurement for wavelengths of infrared radiation as well as sizes of biological cells and bacteria, μm. The longest human chromosome is approximately 10 μm in length.and for grading wool by the diameter of the fibres. The width of a single human hair ranges from approximately 20 to 200
Between 1 μm and 10 μm:
Between 10 μm and 100 μm:
The term micron and the symbol μ were officially accepted for use in isolation to denote the micrometre in 1879, but officially revoked by the International System of Units (SI) in 1967.This became necessary because the older usage was incompatible with the official adoption of the unit prefix micro-, denoted μ, during the creation of the SI in 1960.
In the SI, the systematic name micrometre became the official name of the unit, and μm became the official unit symbol.
Nevertheless, in practice, "micron" remains a widely used term in preference to "micrometre" in many English-speaking countries, both in academic science (including geology, biology, physics, and astronomy) and in applied science and industry (including machining, the semiconductor industry, and plastics manufacturing).[ citation needed ] Additionally, in American English, the use of "micron" helps differentiate the unit from the micrometer, a measuring device, because the unit's name in mainstream American spelling is a homograph of the device's name. In spoken English, they may be distinguished by pronunciation, as the name of the measuring device is invariably stressed on the second syllable, whereas the systematic pronunciation of the unit name, in accordance with the convention for pronouncing SI units in English, places the stress on the first syllable.
The plural of micron is normally "microns", though "micra" was occasionally used before 1950.
The official symbol for the SI prefix micro- is a Greek lowercase mu (μ).In Unicode, there is also a micro sign with the code point U+00B5 (µ), distinct from the code point U+03BC (μ) of the Greek letter lowercase mu. According to the Unicode Consortium, the Greek letter character is preferred, but implementations must recognize the micro sign as well. Most fonts use the same glyph for the two characters.
A typical strand of garden spider silk has a diameter of about 0.003 mm ... Dragline silk (about .00032 inch (.008 mm) in Nephila)
Histogram of Fiber Thickness [micrometer]
A centimetre or centimeter is a unit of length in the metric system, equal to one hundredth of a metre, centi being the SI prefix for a factor of 1/100. The centimetre was the base unit of length in the now deprecated centimetre–gram–second (CGS) system of units.
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints lie on the circle. It can also be defined as the longest chord of the circle. Both definitions are also valid for the diameter of a sphere.
A micron a non-SI name for micrometre (μm).
The nanometre or nanometer is a unit of length in the metric system, equal to one billionth of a metre. The name combines the SI prefix nano- with the parent unit name metre. It can be written in scientific notation as 1×10−9 m, in engineering notation as 1 E−9 m, and as simply 1/1000000000 metres. When used as a prefix for something other than a unit of measure, nano refers to nanotechnology, or phenomena typically occurring on a scale of nanometres.
A metric prefix is a unit prefix that precedes a basic unit of measure to indicate a multiple or fraction of the unit. While all metric prefixes in common use today are decadic, historically there have been a number of binary metric prefixes as well. Each prefix has a unique symbol that is prepended to the unit symbol. The prefix kilo-, for example, may be added to gram to indicate multiplication by one thousand: one kilogram is equal to one thousand grams. The prefix milli-, likewise, may be added to metre to indicate division by one thousand; one millimetre is equal to one thousandth of a metre.
The picometre or picometer is a unit of length in the metric system, equal to 1×10−12 m, or one trillionth (1/1000000000000) of a metre, which is the SI base unit of length.
Yarn is a long continuous length of interlocked fibres, suitable for use in the production of textiles, sewing, crocheting, knitting, weaving, embroidery, or ropemaking. Thread is a type of yarn intended for sewing by hand or machine. Modern manufactured sewing threads may be finished with wax or other lubricants to withstand the stresses involved in sewing. Embroidery threads are yarns specifically designed for needlework.
The millimetre or millimeter is a unit of length in the metric system, equal to one thousandth of a metre, which is the SI base unit of length. Therefore, there are one thousand millimetres in a metre. There are ten millimetres in a centimetre.
The square metre or square meter is the SI derived unit of area with symbol m2.
Mu or my is the 12th letter of the Greek alphabet. In the system of Greek numerals it has a value of 40. Mu was derived from the Egyptian hieroglyphic symbol for water, which had been simplified by the Phoenicians and named after their word for water, to become 𐤌 (mem). Letters that derive from mu include the Roman M and the Cyrillic М. It is also used as coefficient of friction.
Micro- is a unit prefix in the metric system denoting a factor of 10−6. Confirmed in 1960, the prefix comes from the Greek μικρός, meaning "small".
The following are examples of orders of magnitude for different lengths.
In the metric system, a microgram or microgramme is a unit of mass equal to one millionth of a gram. The unit symbol is μg according to the International System of Units; the recommended symbol in the United States when communicating medical information is mcg. In μg the prefix symbol for micro- is the Greek letter μ (Mu).
Pashmina is a fine type of cashmere wool. The textiles made from it were first woven in Kashmir. The name comes from Persian: پشمینه / pašmina, meaning "made from wool". Pashmina came to be known as 'cashmere' in the West because Europeans first encountered this fibre in Kashmir. The wool comes from a number of different breeds of the cashmere goat; such as the changthangi or pashmina goat from the Changthang Plateau in Ladakh region, the malra from the Kargil area in the Ladakh region, the chegu from Himachal Pradesh in the Himalayas of northern India, and the chyangara or Nepalese pashmina goat from Nepal. Often shawls called shahmina are made from this material in Kashmir and Nepal; these shawls are hand spun and woven from the very fine cashmere fibre.
A thousandth of an inch is a derived unit of length in a system of units using inches. Equal to 1⁄1000 of an inch, it is normally referred to as a thou, a thousandth, or a mil.
A micron (micrometre) is the measurement used to express the diameter of wool fibre. Fine wool fibers have low micron value. Fibre diameter is the most important characteristic of wool in determining its value.
Animal fibers are natural fibers that consist largely of particular proteins. Instances are silk, hair/fur and feathers. The animal fibers used most commonly both in the manufacturing world as well as by the hand spinners are wool from domestic sheep and silk. Also very popular are alpaca fiber and mohair from Angora goats. Unusual fibers such as Angora wool from rabbits and Chiengora from dogs also exist, but are rarely used for mass production.
An S number on the label of wool suits or other tailored apparel, wool fabric, or yarn, indicates the fineness of the wool fiber used in the making of the apparel, as measured by its maximum diameter in micrometres. Fiber fineness is one of the factors determining the quality and performance of a wool product. In recent years it has also become an important marketing device used by many mills, garment makers, and retailers. The S number appears as a plural with an s or 's following the number, such as 100s or 100's.
The cubic metre or cubic meter is the SI derived unit of volume. Its SI symbol is m3. It is the volume of a cube with edges one metre in length. An alternative name, which allowed a different usage with metric prefixes, was the stère, still sometimes used for dry measure. Another alternative name, no longer widely used, was the kilolitre.