An isolated differential current shunt measurement probe for a test and measurement system having an isolation barrier between an input side and output side of the probe. The input side is configured to receive a voltage signal across a current shunt connected to a device under test and transmit the voltage signal across the isolation barrier. The output side is configured to receive the voltage signal across the isolation barrier and output the voltage signal to a test and measurement instrument.

Provided is a current measuring device for measuring current, including a conductor (1) adapted to pass current therethrough, and a circuit board (31) with a wire, the wire being adapted to extract a voltage signal from the conductor, in which the circuit board is disposed upright with respect to the conductor.

A resistive material for sensing current contains particles having an electrically insulating property and a metal body having a three-dimensional network enclosing the particles, and a ratio of the metal body to the whole of the resistive material is 30 vol % or more and 80 vol % or less.

At least two redundant analog input units for a measurement current have analog inputs which are connected in parallel and upon which voltage measuring devices directly lie to convert respectively applied voltages into a digital measurement value, wherein in order to detect errors, in particular in order to detect wire breakage, each analog input unit compares its generated measurement value with a threshold and outputs an error message if a measurement value is detected that falls below the threshold, where if the analog input of the analog input unit is in the low-resistance state, then the at least one other analog input unit is additionally caused to assume a current-measuring function and switch the analog input of the analog input unit to a low-resistance state.

Circuits and methods relating to shunt current sensing are provided. A shunt current sensing circuit comprises a shunt resistor for receiving a shunt current. A filtering stage is connected to the shunt resistor and is configured to filter the shunt current. A current sense amplifier is connected to the filtering stage and is configured to receive the filtered shunt current from the filtering stage. The current sense amplifier is configured to sense the filtered shunt current to produce an output voltage. The filtering stage is configured to filter the shunt current such that the output voltage produced by the current sense amplifier (U2) is substantially proportional to the shunt current.

A feedback ammeter, which may be included in a source measure unit or a digital multi-meter, for example, including an operational amplifier having an input and an output and a feedback path electrically coupled between the output and the input of the operational amplifier. The feedback path includes a first non-linear device to allow the measurement of decades of current. The ammeter also includes an amplifier electrically coupled to the input of the operational amplifier and the output of the operational amplifier, a second non-linear device electrically coupled to an output of the amplifier, and a resistor electrically coupled between the second capacitor and the input of the operational amplifier. A constant resistance input impedance is established using the second non-linear device that can adjust the circuit gain.

A shunt resistor 10, 110 includes a flat resistive element 11; a first electrode block 12 that is made of a conductive metal material and is laminated on a lower surface 11a of the resistive element 11; and a second electrode block 13, 113 that is made of a conductive metal material and is laminated on an upper surface 11b of the resistive element 11, in which the second electrode block 13, 113 is a block body including an electrode portion 14 connected to the resistive element 11 and an extension portion 15, 115 extending downward from a side surface of the electrode portion 14.

A line isolating power connector can include a housing for connecting with a power cable and a power source, and wires positioned through the housing that include at least a line wire and a neutral wire. The housing is separated by an aperture into a line conduit and a neutral conduit, and the aperture is sized to receive a portion of a contactless power quality probe such that the power quality probe can be connected around the first line conduit or neutral conduit in order to measure power quality in either the line wire or the neutral wire.

A directional power detector device includes a directional coupling network including a first transmission path connected between a radio frequency (RF) input and an RF output, the first transmission path having a voltage transmission gain A, phase θ and characteristic impedance Zo, a second transmission path having the same voltage transmission gain A, phase θ and characteristic impedance Zo, and a resistor connected between the first transmission path at the RF output and the second transmission path, where the resistor has a value including the characteristic impedance Zo. The directional power detector device further includes a detector diode including an anode connected to the second transmission path and a cathode, a capacitor connected between the cathode of the detector diode and the RF input port, and a detector output connected to the cathode of the detector diode. The detector outputs a DC detector voltage when a forward RF signal is applied to the RF input, and outputs zero DC detector voltage when reverse RF signal is applied to the RF output.

A measuring arrangement for redundantly determining a quantitative value of a current flow includes a first and second current-measuring modules connected in parallel, where the first current-measuring module includes a first analogue input and a first current measurement resistor and a voltage-measuring unit to determine the value of current flowing into the analogue input and through the first current measurement resistor, the second current measuring module includes a second analogue input and a second current measurement resistor and a voltage-measuring unit to determine the value of current flowing into the second analogue input and through the second current measurement resistor, and includes a control unit that detects a gradual change in voltages determined by the voltage-measuring units, and when gradual changes in the voltages that are counter to each other occur, a current-measuring module is excluded from the determination of the quantitative value of the current flow.