Abstract: The present invention relates to an electrical resistor (1), in particular for measuring alternating currents of high frequency, comprising connectors (2, 3) for feeding the current to be measured and connectors (4, 5) for tapping the voltage to be measured and having a layered structure including at least one resistive layer (10), a return conducting layer (11) and any possibly provided insulating layers (7, 12, 21, 22, 24). To obtain a measuring resistance having a particularly good frequency response, a high long-term stability and an efficient cooling and which, moreover, is inexpensive to produce, it is provided for the resistive layer (10) together with the return conducting layer (11) and the possible insulating layers (7, 12, 21, 22, 24) to be part of a multilayered printed circuit board and to comprise a plurality of conductive tracks (14) extending from a central region of the resistive layer (10) towards outside.
Abstract: The invention relates to a device for assisting in the measurement of the earth resistance comprising a ground rod with a wire coiled up on a reel or the like, and electrical connecting means for connecting the wire to the ground rod. To provide such a device which is practical to handle, simple, small, and capable of being produced at low costs, it is provided for the reel or the like to be rotatably mounted on the ground rod. A further improvement results in that the ground rod comprises an offset portion in whose region the reel or the like is rotatably mounted. Preferably, the electrical connecting means between ground rod and wire comprise sliding rings on the rotation axis, the reel or the like. For an rapid exchangeability of the reel, the latter may be mounted on the ground rod by a snap connection.
Abstract: The invention relates to a device for assisting in the measurement of the earth resistance comprising a ground rod with a wire coiled up on a reel or the like, and electrical connecting means for connecting the wire to the ground rod. To provide such a device which is practical to handle, simple, small, and capable of being produced at low costs, it is provided for the reel or the like to be rotatably mounted on the ground rod. A further improvement results in that the ground rod comprises an offset portion in whose region the reel or the like is rotatably mounted. Preferably, the electrical connecting means between ground rod and wire comprise sliding rings on the rotation axis, the reel or the like. For an rapid exchangeability of the reel, the latter may be mounted on the ground rod by a snap connection.