A thermocouple is made out of two metallic conductors, each with different thermoelectric properties. Their operability is based out of the Seebeck effect.
The two conductors welded together at either of their ends, form the reading point, called hot junction. This junction is then inserted in a metallic tube, leaving out the opposite ends of the conductors; these are left loose and form the cold junction. The increase of temperature on the hot junction alters the tension between it and the cold junction: this value in millivolt is then converted into a temperature reading.
The principle according to which resistance temperature detectors (RTD) work via a different mechanism. The sensor’s Ohmic resistance changes proportionally to the temperature to which it is exposed. As the temperature increases, so does the resistance of the sensor. In industrial applications, platinum is the most used material for the production of RTD’s.
Our temperature sensors are available with conventional insulation and compacted MgO insulation.
The conventionally insulated thermocouples and resistance thermometers are suitable when the operating conditions are not particularly heavy. In case of vibrations, strain or pressure, MgO-insulated sensors are advisable.
In these sensors of higher technological level, the hot junction is located inside a metallic tube filled with compacted MgO powder. This technology ensures the maximum reliability of the product and makes it especially desirable for critical industrial processes.
The flexibility and small size of the sensor’s tube, the excellent resistance to vibrations and the fast response time are just some of the many advantages MgO-insulated sensors possess as compared to conventionally insulated ones.