Patent ID: 8330449

Claim:
A clamp-on multimeter for measuring alternating current flow in an electrical conductor of an electrical circuit, comprising: a digital display configured to show a measurement of the alternating current flow in the electrical conductor; a housing including the digital display; a first sensor having a magnetizable material core configured to inductively sense the alternating current without breaking the electrical circuit, the first sensor includes a first clamp portion fixedly coupled to the housing and a second clamp portion pivotally coupled to the first clamp portion, wherein the electrical conductor passes through a gap between the first and second clamp portions in an open arrangement of the first sensor and the first and second clamp portions surround the electrical conductor in a closed arrangement of the first sensor; a second sensor including a Rogowski coil having a non-magnetic core and configured to inductively sense the alternating current without breaking the electrical circuit; a processor disposed in the housing and configured to receive an input signal in a first voltage range and to send an output signal to the digital display; and an integrator disposed in the housing and configured to scale a signal from the second sensor in a second voltage range to the first voltage range; wherein the housing includes the processor, the integrator, and a selector configured to select the input signal to the processor from one of (a) the first sensor and (b) the integrator.