Constantan

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Constantan

Constantan is a copper-nickel alloy usually consisting of 55% Copper

Copper

Copper is a chemical element with the symbol Cu and atomic number 29.It is a ductile metal with very high thermal and electrical conductivity....
and 45% Nickel

Nickel

Nickel is a chemical element, with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge....
. Its main feature is its resistance

Electrical resistance

The electrical resistance of an object is a measure of its opposition to the passage of a steady electrical current. An object of uniform cross section will have a resistance proportional to its length and inversely proportional to its cross-sectional area, and proportional to the resistivity of the material....
which is constant over a wide range of temperatures. Other alloys with similarly low temperature coefficients

Temperature coefficient

The temperature coefficient is the relative change of a physical property when the temperature is changed by 1 Kelvin.In the following formula, let R be the physical property to be measured and T be the temperature at which the property is measured....
are known, such as Manganin

Manganin

Manganin is a trademarked name for an alloy of typically 86% copper, 12% manganese, and 2% nickel. It was first developed by Edward Weston .Manganin foil and wire is used in the manufacture of resistors, particularly Shunt #Use in current measuring, because of its virtually zero temperature coefficient#Temperature coefficient of electrical...
(Cu₈₆Mn₁₂Ni₂).

ll modern strain gauge

Strain gauge

A strain gauge is a device used to measure the Strain of an object. Invented by Edward E. Simmons and Arthur C. Ruge in 1938, the most common type of strain gauge consists of an Electrical insulation flexible backing which supports a metallic foil pattern....
alloy

Alloy

An alloy is a partial or complete solid solution of one or more chemical element in a metallic matrix. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may be homogeneous in distribution depending on thermal history....
s, constantan is the oldest, and still the most widely used. This situation reflects the fact that constantan has the best overall combination of properties needed for many strain gauge applications.

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Encyclopedia

Constantan is a copper-nickel alloy usually consisting of 55% Copper

Copper

Copper is a chemical element with the symbol Cu and atomic number 29.It is a ductile metal with very high thermal and electrical conductivity....
and 45% Nickel

Nickel

Nickel is a chemical element, with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge....
. Its main feature is its resistance

Electrical resistance

Temperature coefficient

Manganin

Constantan alloy

Of all modern strain gauge

Strain gauge

Alloy

Strain (materials science)

In continuum mechanics, the infinitesimal strain theory, sometimes called small deformation theory, small displacement theory, or small displacement-gradient theory, deals with infinitesimal Deformation s of a Continuum mechanics....
sensitivity, or gauge factor

Gauge factor

Gauge factor or strain factor is the product of strain and the quotient of change in strain gauge electrical resistance and unstrained resistance of strain gauge....
, which is relatively insensitive to strain level and temperature

Temperature

In physics, temperature is a physical property of a Physical system that underlies the common notions of hot and cold; something that feels hotter generally has the greater temperature....
. Its resistivity

Resistivity

Electrical resistivity is a measure of how strongly a material opposes the flow of electric current. A low resistivity indicates a material that readily allows the movement of electrical charge....
is high enough to achieve suitable resistance values in even very small grids, and its temperature coefficient

Temperature coefficient

Electrical resistance

The electrical resistance of an object is a measure of its opposition to the passage of a steady electrical current. An object of uniform cross section will have a resistance proportional to its length and inversely proportional to its cross-sectional area, and proportional to the resistivity of the material....
is not excessive. In addition, constantan is characterized by good fatigue life

Fatigue (material)

In materials science, 'fatigue' is the progressive and localized structural damage that occurs when a material is subjected to cyclic loading....
and relatively high elongation capability. It must be noted, however, that constantan tends to exhibit a continuous drift at temperatures above 65 °C

Celsius

Celsius is a temperature scale that is named after the Swedish astronomer Anders Celsius , who developed a similar temperature scale two years before his death....
(150 °F

Fahrenheit

Fahrenheit is a temperature scale named after the physicist Daniel Gabriel Fahrenheit , who proposed it in 1724. Today, the scale has largely been replaced by the Celsius scale; it is still in use for non-scientific purposes in the United States and a few other countries such as Belize....
); and this characteristic should be taken into account when zero

0 (number)

A-Alloy

Very importantly, constantan can be processed for self-temperature compensation to match a wide range of test material coefficients of thermal expansion

Coefficient of thermal expansion

When the temperature of a substance changes, the energy that is stored in the intermolecular bonds between atoms changes. When the stored energy increases, so does the length of the molecular bonds....
. An alloy

Alloy

An alloy is a partial or complete solid solution of one or more chemical element in a metallic matrix. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may be homogeneous in distribution depending on thermal history....
is supplied in self-temperature-compensation (S-T-C) numbers 00, 03, 05, 06, 09, 13, 15, 18, 30, 40 and 50, for use on test materials with corresponding thermal expansion coefficients, expressed in parts per million by length (or µm/m) per kelvin or degree Celsius or degree Fahrenheit.

P alloy

For the measurement

Measurement

Measurement is the process of assigning a number to an attribute according to a rule or set of rules. The term can also be used to refer to the result obtained after performing the process....
of very large strains

Strain (materials science)

Microstrain

Sorry, no overview for this topic
) or above, annealed constantan (P alloy) is the grid material

Material

Materials are substances or components with certain physical properties which are used as inputs to Production, costs, and pricing or manufacturing....
normally selected. Constantan in this form is very ductile

Ductility

Ductility is a mechanical property used to describe the extent to which materials can be deformed deformation without fracture.In material science, ductility specifically refers to a material's ability to deform under tensile stress; this is often characterized by the material's ability to be stretched into a wire....
; and, in gauge lengths of 0.125 in (3 mm) and longer, can be strained to >20%. It should be borne in mind, however, that under high cyclic strains

Strain (materials science)

Electrical resistance

The electrical resistance of an object is a measure of its opposition to the passage of a steady electrical current. An object of uniform cross section will have a resistance proportional to its length and inversely proportional to its cross-sectional area, and proportional to the resistivity of the material....
change with each cycle, and cause a corresponding zero

0 (number)

0 is both a number and the numerical digit used to represent that number in numeral system. It plays a central role in mathematics as the additive identity of the integers, real numbers, and many other algebraic structures....
shift in the strain gauge. Because of this characteristic, and the tendency for premature grid failure with repeated straining, P alloy is not ordinarily recommended for cyclic strain applications. P alloy is available with S-T-C numbers of 08 and 40 for use on metal

Metal

In chemistry, a metal is a chemical element whose atoms readily lose electrons to form positive ions , and form metallic bonds between other metal atoms and ionic bonds between nonmetal atoms....
s and plastic

Plastic

Plastic is the general common term for a wide range of synthetic or semisynthetic organic chemistry solid materials suitable for the manufacture of industrial products....
s, respectively.

Physical properties

Electrical resistivity at room temperature Resistivity Electrical resistivity is a measure of how strongly a material opposes the flow of electric current. A low resistivity indicates a material that readily allows the movement of electrical charge....	4.9 × 10^-7 O·m
Temperature coefficient Temperature coefficient The temperature coefficient is the relative change of a physical property when the temperature is changed by 1 Kelvin.In the following formula, let R be the physical property to be measured and T be the temperature at which the property is measured.... at 20 °C	0.00002 K^-1
Density Density The density of a material is defined as its mass per unit volume. The symbol of density is ....	8.9 × 10³ kg/m³
Melting point Melting point The melting point of a solid is the temperature range at which it changes states of matter from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium....	1221 to 1300 °C
Specific heat capacity Specific heat capacity Specific heat capacity, also known simply as specific heat, is the measure of the energy required to increase the temperature of a of a substance by a certain Celsius#Temperatures_and_intervals....	0.39 J/(g·K)
Thermal conductivity Thermal conductivity In physics, thermal conductivity, , is the List of materials properties of a material that indicates its ability to conduct heat. It appears primarily in Heat conduction#Fourier's law for heat conduction.... at 23°C	19.5 W/(m.K)
Linear coefficient of thermal expansion Coefficient of thermal expansion When the temperature of a substance changes, the energy that is stored in the intermolecular bonds between atoms changes. When the stored energy increases, so does the length of the molecular bonds.... at 20-100°C	14.9 × 10^-6 K^-1
Tensile strength Tensile strength Tensile strength , or is the Stress at which a material breaks or permanently deforms. Tensile strength is an Intensive and extensive properties and, consequently, does not depend on the size of the test specimen....	400-590 MPa
Elongation at fracture Fracture A fracture is the separation of an object or material into two, or more, pieces under the action of stress .The word fracture is often applied to bones of living creatures, or to crystals or crystalline materials, such as gemstones or metal....	<45%
Elastic modulus Elastic modulus An elastic modulus, or modulus of elasticity, is the mathematical description of an object or substance's tendency to be deformed elastically when a force is applied to it....	162 Gpa

Temperature Measurement

Constantan is also used to form thermocouple

Thermocouple

A thermocouple is a junction between two different metals that produces a voltage related to a temperature difference. Thermocouples are a widely used type of list of temperature sensors and can also be used to convert heat into electric power....
s with wires made of iron, copper, or chromel

Chromel

Chromel is an alloy made of approximately 90 percent nickel and 10 percent chromium that is used to make the positive conductors of ANSI Type E and K thermocouples....
.

Constantan

Constantan alloy

A-Alloy

P alloy

Physical properties

Temperature Measurement

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