The tester uses a new generation of four semi-double power loop integral conversion ICs, with precision bandgap reference, range accuracy, high precision, stable and reliable performance and capacity high anti-interference. High temperature can be used to measure power supply, USB interface, mobile phone charger, U disk and other USB-powered products. Can easily measure the working current of the output voltage of the USB port and equipment. Small in size, without power supply and other auxiliary equipment, plug and play also detects the USB charger output voltage and current are standard and suitable for factories, laboratories and users. USB powered devices can be used to measure air, voltage loads, voltage and the operating current of the equipment USB terminal elements.