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All over the world industries test and control the temperature that builds up during operation in the rotary furnace and the heating axis. The laboratories test new materials for their thermal properties, as to use for the purpose of thermal couples. But we need to also observe and record relevant data and so cannot do without the use of slip ring assembly. But the essential question or objective in engineering is, how do we choose a slip ring or what are the conditions to be kept in mind while choosing a slip ring so as to reduce the error to a minimum. If we choose the wrong slip ring it would cause great loss. There are many factors responsible for choosing the right slip ring based on its thermal resistance.
Properties influencing the decision of slip rings
The thermal resistance of the material and the temperature of the material are based on the metallic characteristics of the conductor. The resistance increases with the increase in temperature. In most cases, the thermal resistance is made of pure metal. Platinum and copper were the most commonly used materials but now nickel, manganese; rhodium and other materials are also being used.
Thermal Resistance Type
.Ordinary Thermal Resistance
From the measurement principle, we know the thermal resistance, but the temperature change directly results to change in thermal resistance. Therefore, a change of the change of temperature of the heating resistor will cause wire resistance.
.Face Thermal Resistance
Face thermal resistance is the temperature sensing element caused by the resistance wire wound around the end face of the thermometer. When compared with general axial thermal resistance, can more accurately reflect the actual temperature at the end face and other bearings and other parts of the machine.
.Armored Thermal resistance
It is the temperature sensing or resistive element, lead, stainless steel casing of a solid body, insulation material. There are following advantages in this resistance as compared to the ordinary thermal resistance. They have a small size, thermal inertia, easy to install, resistance to vibration and shock, able to bend and a long service life, etc.
Flameproof Heat Resistance
Flameproof Heat Resistance is achieved through a special junction box structure. There are explosions inside the shell. These are made by an explosive mixture, caused due to spark or arching or other reactions which take place inside the confinement of the junction box. The production site will not see any effect of the explosion. The flameproof heat resistance is used in measuring the temperature of explosive dangerous parts. In these conditions, the need to use the special slip rings arises.
Depending on the different requirements of the thermocouples the slip ring manufacturer companies develop slip rings made of different designs and material. The different combinations are used like the difference in the contact material, design of the rings and the contact and the wires.