J type thermocouple has excellent linearity, thermoelectric emfs larger, high sensitivity, stability and uniformity is better.

J type thermocouple

Type J thermocouple,its positive (JP) under the name of chemical components in pure iron, copper anode (Jacqueline Nottingham) for nickel alloy, often be vaguely called constantan, under its name chemical components: 55 percent of copper and nickel and 45% of small but very important manganese, cobalt, iron and other elements,so constantan cannot use EN and TN to replace. Iron - Constantan thermocouple coverage of measurement temperature range for - 200 ~ 12 °C, but usually use temperature range of 0 ~ 750 °C.

J type can be used in vacuum, oxidation thermocouple, restore and inert atmosphere, but positive iron under high temperature oxidation faster, so use temperature is restricted, also cannot directly without reserve at high temperatures for sulfide atmosphere.