Thermocouples wire

Thermocouple wire – made ​​from alloys chromel grades T and TM, alumel, Constantan, Copel.

All properties of the wire depends on the percentage composition of the components. The most important properties of the alloy is low density, heat resistance, very low temperature coefficient of electric resistance, high thermoelectric power, high electrical resistivity;

Little about each alloy separately.

Chromel is an alloy of nickel and chromium, which has a good combination of thermoelectric properties and high heat resistance. Consists of about 10 % Cr, 1 % of Co, and impurities to 0,3% Fe and 0.2 % C.

Alumel is an alloy which contains about 1.8-2.5 % aluminum, 0,85-2,0 % silicon, 1.8-2.2% manganese, 0.6-1.0 % cobalt, and the rest – Nickel. Alloy and plastic retains its strength for very long. Alumel used as negative thermoelectrodes thermocouples chromel- alumel and a compensating wires.

Constantan is an alloy of Cu with Ni and 40 % Mn 1,5%, which refers to an alloy with high electrical resistance , which is weakly dependent on temperature. From this alloy manufactured thermocouples and different heating elements instrumentation rheostats.

Kopel is an alloy of copper, iron and chromel, which has properties similar to kontantan and sufficiently large thermoelectric power. Temperature coefficient of electrical resistance Kopel almost zero, while it maintains temperature and heat-resisting 600 °С made from this alloy thermocouple Chromel – Copel – paced and iron – Copel.

Thermocouple wire used to make the thermocouple. This thermocouple temperature transducer, which consists of two wires of different alloys, soldered with one end and placed in a medium for measuring temperatures, and the other two are placed at the end of the thermostat.

There are several types of thermocouples that measure various values ​​of temperatures:

Thermocouple – Copel – Chromel (TCA) measures temperatures from -200 to 800°C;

Iron- constantan thermocouple, measures the lowest temperatures – up to -190°C;

Thermocouple iron- Kopel, measures temperatures from 0 to 760°C;

Constantan thermocouple – Chromel (THC), measures temperatures from -40 to 900°C;

A copper- constantan thermocouple, measures the temperature of 250 to 300°C;

Alumel thermocouple – Chromel (TCA), measures temperatures from -200 to 1000°C;

Tungsten- rhenium thermocouple, measuring the high temperature to 3000°C.