Test points of transformer ratio tester

        The ratio tester is an instrument that measures the transformer ratio. And it can be used to measure the transformation ratio and wiring group of various three-phase transformers. It is also widely used in industry. Then Xiaobian mainly introduces the test points of transformer ratio tester, hope to help everyone.

        When a certain DC voltage is used to pressurize the material to be tested, the current on the material to be tested does not instantaneously reach a stable value, but has an attenuation process. At the same time of pressurization, a large charging current flows, followed by a relatively slow absorption current for a long time, and finally a relatively stable electric current flow is achieved. The higher the measured resistance value, the longer the time to reach equilibrium. Therefore, in order to correctly read the measured resistance value during measurement, the value should be read after stabilization or the reading value after 1 minute of pressurization.

       The resistance (rate) value of the dielectric material generally cannot be kept constant over a wide range of voltages, ie Ohm’s law does not apply. Under normal temperature conditions, in the lower voltage range, the electrical conductivity increases linearly with the increase of the applied voltage, and the resistance of the material remains unchanged. After a certain voltage is exceeded, the increase of the electric conduction current is far faster than the increase of the test voltage due to the increase of the ionization motion, and the resistance value of the material rapidly decreases. It can be seen that the higher the applied test voltage, the lower the resistance value of the material, so that the resistance values of the materials tested under different voltages may have a large difference.