Electrical conductivity can be defined as the electrical current applied to the conductive material to move over long distances with suitable cables. When a potential difference between the two ends of a conductive material is applied, an electric field is formed in the conductor and a force acts on the electrons. The magnitude of the electric field is directly proportional to this force. The direction is in the opposite direction to the electric field.

Under normal conditions, electrons should not encounter any obstacles during the conduction of electricity, that is, they must move without being attached to the obstacles. However, atoms in the conductor interfere with this movement and if they encounter electrons, they cause them to scatter in different directions and sometimes backward. In such a case, part of the energy of electrons carrying or transmitting current begins to pass into atoms. This causes the conductor to heat up.

As the energy transferred to a conductor increases, the current decreases and the resistance of the conductive material starts to increase to the same extent. The atoms contained in the solids do not exhibit displacement movements, such as atoms in the gas, and are constantly vibrating. As a result, as the temperature, a measure of kinetic energy, increases, the vibration amplitude of atoms increases and the frequency of collision of electrons carrying current in the conductor increases with atoms. As a result of this effect, the amount of energy converted to heat, ie temperature, causes the electrical conductivity to decrease.

Several laboratories, which are authorized by national or international accreditation bodies, carry out heating tests among many electrical tests. In doing so, laboratories must operate in accordance with the criteria and conditions determined by the current legal regulations and standards developed by domestic and foreign organizations.

In addition, during testing, laboratories must comply with the standards of TS EN ISO / IEC 17025 General Requirements for the Competence of the Testing and Calibration Laboratories.