Editing Constantan (section)

==Constantan alloy==
Of all alloys used in modern [[strain gauge]]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. This alloy has, for example, an adequately high [[strain (materials science)|strain]] sensitivity, or [[gauge factor]], which is relatively insensitive to strain level and [[temperature]]. Its [[resistivity]] ({{val|5.00|e=−7|u=Ω·m}})<ref name=Davis158/> is high enough to achieve suitable resistance values in even very small grids, and its [[temperature coefficient]] of [[electrical resistance|resistance]] is fairly low. In addition, constantan is characterized by a good [[Fatigue (material)|fatigue life]] and relatively high [[elongation (materials science)|elongation]] capability. However, constantan tends to exhibit a continuous drift at temperatures above {{convert|65|C|F}};<ref>{{cite book |title=Strain Gage Users' Handbook |last=Hannah |first=R.L. |publisher=Springer |year=1992 |isbn=978-0412537202 |location=New York |page=50}}</ref> and this characteristic should be taken into account when [[0 (number)|zero]] stability of the strain gauge is critical over a period of hours or days. Constantan is also used for electrical resistance heating and [[thermocouple]]s.<ref name="keatsmfg.com">{{cite web |url=https://www.keatsmfg.com/blog/working-with-chromel-alumel-constantan/ |title=Working with Chromel, Alumel & Constantan |date=2015-03-12 |website=Keats Manufacturing Co. |language=en-US |access-date=2016-05-18}}</ref>