Abstract: A digital multimeter comprising a measured object input terminal, conversion circuit for a fast analog/digital converter, microprocessor, auxiliary program-controlled voltage or current source, potential divider network, electronic switches, and display. Compared with conventional multimeters, the adoption of fast analog/digital conversion technology as well as a method that applies an auxiliary power supply at the time of a passive analog measurement allows for measuring different responses between input terminals after an auxiliary power supply is applied, thus being able to automatically determine the characteristics and size of the measured object.

Abstract: A digital multimeter comprising measured object input terminal, conversion circuit of fast analog/digital converter, microprocessor, auxiliary program-controlled voltage or current source, potential-divider network, electronic switches, and display. Compared with conventional multimeters, the adoption of fast analog/digital conversion technology as well as method that applies auxiliary power supply at the time of passive analog amount measurement allows for measurement of different responses between input terminals after auxiliary power supply is applied, thus being able to automatically determine the characteristics and size of the measured object.

Abstract: Taught herein is a current measuring device, comprising an insulating cover with an upper opening; a magnetic component; and a Hall-effect component; wherein the magnetic component comprises a left magnetic portion and a right magnetic portion forming an upper gap and a lower gap; the Hall-effect component is disposed in the lower gap; and both the magnetic component and the Hall-effect component are received in the insulating cover. Compared with the prior art, the current measuring device of the invention has a lower magnetic reluctance, which introduces higher measurement sensitivity and accuracy, along with a greater anti-interference ability.