Abstract: A measuring circuit for determining the magnitude of a current flowing through a conductor, the measuring circuit having an input terminal pair that can be connected to the current transformer with a first switch, which connects a measuring resistor between the input terminals in a current measuring position, and which, in a voltage measuring position, separates the measuring resistor from at least one of the input terminals, and having an output terminal pair, at which, alternatively, a voltage-dependent measuring voltage present at the input terminal pair or a current-dependent measuring voltage present at a first measuring point of the measuring resistor can be tapped. The measuring circuit includes a changeover switch which can be switched synchronously with the switch. The changeover switch is used to connect an output terminal to the first measuring point in the current measuring position, and to the second measuring point in the voltage measuring position.

Abstract: A device for fastening a bar-shaped sensor, in particular a flow sensor, to a component, which has a fastening section that can be inserted into a fastening opening of the component, a hole extending through the fastening section and a retaining section for inserting the sensor, wherein the hole is open to an end face of the fastening section and to an end face of the retaining section. In order to be able to change out a sensor with a reproducible rotational position, it is proposed that the wall of the hole in the fastening section have an opening, into which a section of the edge of the fastening opening protrudes in the free cross-section of the hole for rotationally fixating the sensor in the hole.