A graduation is a marking used to indicate points on a visual scale, which can be present on a

container A container is any receptacle or enclosure for holding a product used in storage, packaging, and transportation, including shipping. Things kept inside of a container are protected on several sides by being inside of its structure. The term ...

, a measuring device, or the axes of a line plot, usually one of many along a line or curve, each in the form of short line segments perpendicular to the line or curve. Often, some of these line segments are longer and marked with a numeral, such as every fifth or tenth graduation. The scale itself can be linear (the graduations are spaced at a constant distance apart) or nonlinear. Linear graduation of a scale occurs mainly (but not exclusively) on straight measuring devices, such as a rule or measuring tape, using units such as

inch The inch (symbol: in or prime (symbol), ) is a Units of measurement, unit of length in the imperial units, British Imperial and the United States customary units, United States customary System of measurement, systems of measurement. It is eq ...

es or

millimetre 330px, Different lengths as in respect of the electromagnetic spectrum, measured by the metre and its derived scales. The microwave is between 1 metre to 1 millimetre. The millimetre (American and British English spelling differences#-re, -er, i ...

s. Graduations can also be spaced at varying spatial intervals, such as when using a logarithmic, for instance on a

measuring cup A measuring cup is a List of food preparation utensils, kitchen utensil used primarily to measure the volume of liquid or bulk solid cooking ingredients such as flour and sugar, especially for volumes from about 50 millilitre, mL (approx. 2& ...

, can vary in scale due to the container's non-

cylindrical A cylinder () has traditionally been a Solid geometry, three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a Prism (geometry), prism with a circle as its base. A cylinder may ...

shape.

Graduations along a curve

Circular graduations of a scale occur on a circular arc or limb of an instrument. In some cases, non-circular curves are graduated in instruments. A typical circular arc graduation is the division into angular measurements, such as degrees, minutes and seconds. These types of graduated markings are traditionally seen on devices ranging from compasses and clock faces to alidades found on such instruments as

telescopes A telescope is a device used to observe distant objects by their emission, Absorption (electromagnetic radiation), absorption, or Reflection (physics), reflection of electromagnetic radiation. Originally, it was an optical instrument using len ...

, theodolites,

inclinometers An inclinometer or clinometer is an measuring instrument, instrument used for measuring angles of slope, elevation, or depression (geology), depression of an object with respect to gravity's direction. It is also known as a ''tilt indicator'', ' ...

, astrolabes, armillary spheres, and

celestial spheres The celestial spheres, or celestial orbs, were the fundamental entities of the cosmological models developed by Plato, Eudoxus, Aristotle, Ptolemy, Copernicus, and others. In these celestial models, the apparent motions of the fixed star ...

. There can also be non-uniform graduations such as logarithmic or other scales such as seen on circular slide rules and graduated cylinders. Slide rule scales back

Manufacture of graduations

Graduations can be placed on an instrument by

etching Etching is traditionally the process of using strong acid or mordant to cut into the unprotected parts of a metal surface to create a design in intaglio (incised) in the metal. In modern manufacturing, other chemicals may be used on other type ...

, scribing or engraving,

painting Painting is a Visual arts, visual art, which is characterized by the practice of applying paint, pigment, color or other medium to a solid surface (called "matrix" or "Support (art), support"). The medium is commonly applied to the base with ...

printing Printing is a process for mass reproducing text and images using a master form or template. The earliest non-paper products involving printing include cylinder seals and objects such as the Cyrus Cylinder and the Cylinders of Nabonidus. The ...

or other means. For durability and accuracy, etched or scribed marks are usually preferable to surface coatings such as paints and inks. Markings can be a combination of both physical marks such as a scribed line and a paint or other marking material. For example, it is common for black ink or paint to fill the grooves cut in a scribed rule. Inexpensive plastic devices can be molded and painted or molded with two or more colors of plastic used. Some rather high-quality devices can be manufactured with plastic and reveal high-precision graduations. Graduations traditionally have been scribed into an instrument by hand with a sharp, hard

tool A tool is an Physical object, object that can extend an individual's ability to modify features of the surrounding environment or help them accomplish a particular task. Although many Tool use by animals, animals use simple tools, only human bei ...

.Daumas, Maurice, ''Scientific Instruments of the Seventeenth and Eighteenth Centuries and Their Makers'', Portman Books, London 1989 Later developments in devices such as dividing engines allowed the process to be automated with greater precision. Modern devices can be stamped, cut on a

milling machine Milling is the process of machining using rotary cutters to remove material by advancing a cutter into a workpiece. This may be done by varying directions on one or several axes, cutter head speed, and pressure. Milling covers a wide variety of ...

or with a CNC machine. In the case of stamping, the master has the precision built into itself and the stamped device is as accurate as the stamping process allows. Similarly, molding of plastic can be as precise as the mold process. With proper concern for such effects as thermal expansion or contraction and shrinkage, the precision can be very high.

US graduation style

The US graduation style of an instrument was a Federal standard for codes used by manufacturers to quickly determine which types of scales are marked on the instrument. Other commonly recognized styles are:{{Citation needed, date=February 2019 * 30–1 mm, 0.5 mm *31–1 mm, 0.5 mm, 1/32″, 1/64″ *34–1 mm, 0.5 mm, 1/10″, 1/50″ *35–1 mm, 0.5 mm on both sides *35E—1 mm, 0.5 mm on both sides, plus mm on both ends on one side *36—1/32″ and 1 mm on one side; 1/64″ and 1 mm on other side *37–1 mm, 0.5 mm *37E—1 mm, 0.5 mm on both sides, plus mm on both ends on one side, Single row inch figure *E/M—edge 1: 1/10″, edge 2: 1/100″, edge 3: 1.0 mm, edge 4: 0.5 mm *3R—1/64″, 1/50″, 1/32″, 1/10″ * 4R—1/64″, 1/32″, 1/16″, 1/8″ * 5R—1/100″, 1/64″, 1/32″, 1/10″ * 6R—1/32″, 1/64″, 1/10″, 1/100″ * 7R—1/100″,1/64″, 1/32″, 1/16″ *9R—1/16″, 1/32″, 1/64″ *10R—1/32″, 1/64″ (quick-reading) *10R/D—1/64″, 1/32″, Decimal Equivalency Table Graduation * 12R—1/100″, 1/64″, 1/50″, 1/32″ * 16R—1/100″, 1/64″, 1/50″, 1/32″ Suffix key: * R = Rapid Read (32nd & 64th graduations marked with number values) * E = End Graduations (Graduations appear on end edge/edges) * ME = Metric/English (Metric units in preferred position) * E/M = English/Metric (English units in preferred position)

References

Measuring instruments Signage

Graduations along a curve

Manufacture of graduations

US graduation style

See also

References