Abstract: A system for measuring a current intensity of a current flowing through an electrical conductor (10), where the system includes a first component (1), which has the electrical conductor (10), and a second component (2), which is separate from the first component (1) and has an evaluation device (23), and a magnetic field-sensitive sensor element (3) and a connection line (4). The connection line (4) is a light guide. The sensor element (3) is non-releasably connected to the first end of the connection line (4) and/or to the first component (1). In the operating state, the two components 1(, 2) are DC-isolated from one another and are releasably connected to one another by means of the connection line (4) by way of a light-guiding connection, where the power supply to the magnetic field-sensitive sensor element (3) by the second component (2) and/or transmission of sensor data from the magnetic field-sensitive sensor element (3) to the evaluation device (23) is ensured by the light-guiding connection.

Abstract: A scalar magnetometer includes a sensor element, a circuit carrier, a pump radiation source, a radiation receiver and evaluation means. The pump radiation source emits pump radiation. The sensor element preferably includes one or more NV centers in diamond as paramagnetic centers. This paramagnetic center emits fluorescence radiation when irradiated with pump radiation. The radiation receiver converts a intensity signal of the fluorescence radiation into a receiver output signal. The evaluation means detects and/or stores and/or transmits the value of the receiver output signal. The material of the circuit carrier is preferably transparent for the pump radiation in the radiation path between pump radiation source and sensor element and transparent for the fluorescence radiation in the radiation path between sensor element and radiation receiver. The components sensor element, pump radiation source, radiation receiver and evaluation means are preferably mechanically attached to the circuit carrier .

Abstract: A fault current switch with a total current converter (W), whose primary circuit (1) consists of the incoming and outgoing lines of the circuit to be monitored, and whose secondary winding (2) is connected with a test circuit (P), with an electromagnetic switching device (H) for shutting off the circuit to be monitored if a fault current appears, with the working current of the holding device (H) being switchable by a switch (S1) that is supplied for the purpose with a control signal by test circuit (P), and with a power supply (EV1) for the test circuit (P) and the switch (S1). In order to make such a fault current switch both less prone to wear and also more functionally reliable, a second switch (S2) is connected in parallel with the first switch (S1), likewise for switching a working current of the switching device (H), the second switch (S2) being energized by the test circuit (P) with a second control signal that differs from the first control signal.