manganin

{{this|an alloy|the antimicrobial peptides|magainin}}

{{Infobox material

| name = Manganin

| image = 1900 Reichenstalt Pattern Resistor.jpg

| image_size =

| alt =

| caption = A manganin resistor made in 1900 at the Bushy House physics laboratory.

| type = Copper-manganese alloy

| density = {{val|8.4|u=g/cm3}}

| flammability =

| limiting_oxygen_index =

| water_absorption_eq =

| water_absorption_24h =

| radiation_resistance =

| uv_resistance =

| youngs_modulus =

| tensile_strength = 300–600 MPa

| elongation = <50%

| compressive_strength =

| poissons_ratio =

| hardness_rockwell =

| izod_impact_strength = 107 J/m

| notch_test =

| abrasive_resistance_note =

| abrasive_resistance =

| coeff_friction =

| speed_of_sound =

| melting_point = 1020 °C

| glass_transition =

| heat_deflection_temp_note =

| heat_deflection_temp =

| vicat_note =

| vicat =

| vicat_a =

| vicat_b =

| upper_working_temp =

| lower_working_temp =

| heat_transfer_coeff =

| thermal_conductivity_note = at {{val|23|u=degC}}

| thermal_conductivity = 22 W/(m·K)

| thermal_diffusivity_note =

| thermal_diffusivity =

| linear_expansion = {{val|14|-|19|e=-6|u=K⁻¹}}

| specific_heat = 0.097 cals/gm

| dielectric_constant_note =

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| relative_permeability =

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| dielectric strength =

| dissipation_factor_note =

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| surface_resistivity =

| volume_resistivity = 43–48 μΩ⋅cm

| chem_res_acid_c =

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| chem_res_alkali =

| chem_res_aromatic =

| chem_res_grease_oil =

| chem_res_haloalkane =

| chem_res_halogen =

| chem_res_ketone =

| gas_perm_temp = {{val|20|u=degC}}

| gas_perm_N =

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| gas_perm_CO2 =

| gas_perm_H2O =

| price =

| footnotes = Source{{cite web|title=Manganin 230 Shunt Wire|url=http://www.calfinewire.com/datasheets/100115-manganin230shunt.html|website=California Fine Wire Co|accessdate=13 January 2018|language=en}}

}}

Manganin is a trademarked name for an alloy of typically 84.2% copper, 12.1% manganese, and 3.7% nickel. It was first developed by Edward Weston in 1892, improving upon his Constantan (1887).

Manganin foil and wire is used in the manufacture of resistors, particularly ammeter shunts, because of its virtually zero temperature coefficient of resistance value{{Cite web|url=http://www.goodfellow.com/catalogue/GFCat2H.php?ewd_token=09GRBJvlw6lL5lDbZC1qWnos3v9ad5&n=kCvbg9HE4EQs6Xg56ttKPuupoT1SdP&ewd_urlNo=GFCat2L3&Head=CU06|title=Goodfellow Technical Information Manganin® - Resistance Alloy|website=www.goodfellow.com|access-date=2016-09-11}} and long term stability. Several Manganin resistors served as the legal standard for the ohm in the United States from 1901 to 1990.{{Cite web |url=https://nvlpubs.nist.gov/nistpubs/sp958-lide/063-065.pdf |title=Stability of Double-Walled Manganin Resistors |access-date=2007-04-30 |archive-url=https://web.archive.org/web/20240930055258/https://nvlpubs.nist.gov/nistpubs/sp958-lide/063-065.pdf |archive-date=2024-09-30 |url-status=live}} Manganin wire is also used as an electrical conductor in cryogenic systems, minimizing heat transfer between points which need electrical connections.

Manganin is also used in gauges for studies of high-pressure shock waves (such as those generated from the detonation of explosives) because it has low strain sensitivity but high hydrostatic pressure sensitivity.{{cite web |title=Special Use Sensors - Manganin Pressure Sensor |url=http://web.sensor-ic.com:8000/ZLXIAZAI/VISHAY/thumb_2011032859967085.pdf |website=web.sensor-ic.com |publisher=Vishay |access-date=15 April 2023 }}{{Dead link|date=April 2024 |bot=InternetArchiveBot |fix-attempted=yes }}