The Gefran brand temperature sensors offered by CES cover a wide temperature range (-200ºC ÷ +2000ºC), which allows them to be used in many manufacturing sectors such as:
- Medical laboratories
- Woodworking industry
- Food production
- Pharmaceutical industry
- Aluminum, ceramics and heat treatment processes
- Metallurgical industry
- Industrial furnaces
Thermocouples - characteristics
Thermoelectric thermometers, commonly known as thermocouples (TCs), consist of two metallic conductors made of different but chemically homogeneous materials that generate an electromotive force (SEM) depending on the temperature.
The principle of thermocouples is the thermoelectric effect of Seebeck, who discovered that in a circuit formed by two different metal conductors A and B, when the two junctions have different temperatures T1 and T2, current circulates in the circuit, produced by an electromotive force whose magnitude is directly proportional to the temperature difference between the two junctions.
Gefran thermocouples cover all the most popular types of temperature sensors. It is also possible to manufacture thermocouples in three Tolerance Classes 1, 2 and 3 in compliance with IEC 60584-2 standards.
TR resistance thermometers
Metal resistance thermometers, commonly called TR thermistors, are based on the principle that the resistance R of a metal conductor depends on:
R=p*I/A
Where:
R - conductor resistance
A - conductor surface
I - conductor length
p - resistivity of the conductor
As the temperature changes, the resistance of the conductor Rt changes, which, relative to the initial resistance Ro, can be formulated using the following relationship:
Rt = Ro*(1+αt)
Where:
Rt - resistance at tºC
Ro - resistance at 0ºC
a - temperature coefficient
t - temperature
The temperature coefficient α depends on the type of metal used to make a resistance thermistor. The most commonly used material for metal thermistors is platinum (Pt), due to its greater resistance to oxidation, electrical resistivity and repeatability in a wide variety of applications. The most popular elements have a value of 100 ohms at 0 ºC and are therefore referred to as Pt100.
Gefran thermistors include all the most popular types of metal thermistors with two-, three- or four-wire connections in tolerances of CLASS 1 DIN, 1/2 DIN, 1/3 DIN, 1/5 DIN and 1/10 DIN according to IEC 751-DIN 43760.