A sensor apparatus for determining and/or monitoring a process variable of a medium in a containment includes: a crystal body including at least one defect; a magnetic field system for producing a magnetic field in the region of the crystal body and in the region of the medium within the containment, wherein the crystal body and the magnetic field system are arrangeable from the outside at a wall of the containment; a detection unit for detecting a magnetic field-dependent, fluorescent signal from the crystal body, wherein the detection unit has an excitation unit for optical exciting of the defect and a detector for detecting the fluorescent signal; and an evaluation unit for ascertaining at least one piece of information concerning the process variable based on the fluorescent signal.

A contacting device is provided for an impedance limit switch, the contacting device including: a printed circuit board having an electrically conductive contact surface; a radially disposed annular spring configured to establish electrical contact between the electrically conductive contact surface of the printed circuit board and at least one electrode of the impedance limit switch; and a non-conductive housing element. An impedance limit switch is also provided, including the contacting device; an electronic cup; and a measuring head configured to carry out a conductive and/or capacitive measurement and to record measurement data, the contacting device being configured to transmit the measurement data from the measuring head to the electronic cup via the contacting unit.

A system and method for remotely monitoring a sump pump are disclosed. The system includes a controller, a sensor chamber, and a remote device in communication with the control system that can toggle an operating signal to the sump pump. The operating signal is an increase pump speed signal or a decrease pump speed signal, each of the increase pump speed signal and the decrease pump speed signal associated with operating the sump pump in response to a water fill time exceeding a threshold value. The system also includes a wireless controller configured to receive monitoring instructions and to transmit sump pump status data to the remote device. The system further includes a notification system designed to generate and transmit an alert to the remote device when the measured water level exceeds a water level set point value, where a user configures the water level set point value in the remote device.