Measurement device and measurement method thereof

A measurement device comprising:

• a power supplier comprising a first terminal through which a first power voltage is output and a second terminal through which a second power voltage is output, the power supplier being configured to receive a first current from the first terminal to measure a power current of a display device and to receive a second current from the second terminal to measure a luminance of the display device;
• a switching circuit comprising a first switch configured to selectively connect a power terminal of the display device to the first terminal or an internal voltage terminal of the display device through which an internal voltage of the display device is output;
• and
• a luminance sensing circuit configured to receive the second power voltage and to generate the second current corresponding to the luminance of the display device,
• wherein the power supplier comprises:
• a control circuit configured to generate an initial power voltage;
• a power amplifier configured to receive a sum of the initial power voltage and a feedback voltage and to output the first power voltage;
• a current meter configured to measure the power current;
• a voltage meter configured to measure the first power voltage at the first terminal;
• a luminance meter configured to measure the luminance;
• and
• a feedback controller configured to generate the feedback voltage based on the initial power voltage and the first power voltage.