An optical operating fluid detector for optical detection of operating fluid for a hand-guided garden, forestry and/or construction machining appliance includes a light source, an operating fluid line and a light receiver. The light source is designed for radiation of rays of light. The operating fluid line is designed for optical interaction of rays of light from the light source with operating fluid in line for the optical detection of operating fluid. The light receiver is designed for differing reception of rays of light from the line in dependence on the presence or the absence of operating fluid in the line. The operating fluid detector has an optical deflecting device. The deflecting device is designed for deflection of rays of light from the light source to the operating fluid line and/or for deflection of rays of light from the line to the light receiver. The operating fluid line is designed for differing diversion of rays of light from the light source in dependence on the presence or the absence of operating fluid in the line for optical detection of operating fluid.

A sensor device for determining and/or monitoring a process variable of a medium in a container includes: a crystal body having at least one defect; and a magnetic field device for generating a magnetic field, the magnetic field device arranged such that a magnetic field can be generated in the region of the crystal body and in the region of the medium located within the container, so that a change of the magnetic field in the region of the crystal body is amplified, wherein the crystal body and the magnetic field device are arranged from the outside on a wall of the container. A method for determining and/or monitoring a process variable of a medium in a container using the sensor device is also disclosed.

Provided is a system (1) for autonomous filling of a container (5), comprising: a fluid dispenser (9); a distance (11); a plurality of electromagnetic radiation emitters (2) and receivers (3); a user interface (6) configured to receive a desired percentage of the height of the container (5) to be filled with liquid; and a controller electronically connected to the distance sensor (11), the plurality of emitters (2) and receivers (3), the user interface (6) and the fluid dispenser (9).

Embodiments described herein generally relate to devices, systems and methods for measuring a volume or number of doses remaining in a drug delivery device that is used for delivering a dose to a patient. In some embodiments, a dose measurement system for measuring the liquid volume in a container includes a light guide disposed and configured to reflect electromagnetic radiation toward the container. The dose measurement system also includes a light guide disposed and configured to emit electromagnetic radiation into the light guide. A plurality of sensors are located in the apparatus that are optically coupleable to the light guide and are disposed and configured to detect the electromagnetic radiation emitted by at least a portion of the light guide. The apparatus also includes a processing unit configured to receive data representing the portion of the detected electromagnetic radiation from each of the plurality of sensors. The processing unit is further operable to convert the received data into a signature representative of the electromagnetic radiation detected by the plurality of sensors.

A portable, self-contained beverage apparatus includes a container assembly having a known storage capacity for storing a consumable liquid, and a dispensing assembly disposed within the container assembly that dispenses variable, non-zero quantities of additives into the consumable liquid. The dispensing assembly includes multiple apertures structured and arranged to retain vessels containing the additives to be dispensed into the consumable liquid. The beverage apparatus also includes a level sensor disposed within the container assembly that determines a consumable liquid level of the consumable liquid stored in the container assembly. In certain embodiments, one or more positive displacement pumping mechanisms are configured to pump additive liquid from additive containers into a beverage chamber.

A device for measuring the state of a phase change material inside a vessel, the device includes at least one optical fiber arranged inside the vessel, the optical fiber including a cladding around a core, a light source emitting light coupled into a first end of the at least one optical fiber at a wavelength , optical measuring devices for measuring the amount of light at the output at a second end of the at least one optical fiber. The at least one optical fiber also includes a plurality of sections with the cladding removed so that at these sections the core is in direct contact with the phase change material inside the vessel and where the refractive index at the wavelength of the core is higher than that of the phase change material in a first phase and lower in a second phase.

An airplane fuel level optical sensor using one side-emitting plastic optical fiber (SPOF) and two fluorescent plastic optical fibers (FPOFs) to detect the airplane fuel level without using any electrically conductive component or element placed inside the fuel tank. This dual-FPOF sensor is capable of achieving high resolution and high accuracy with a one-time calibration in the actual airplane's fuel tank environment. One embodiment of the dual-FPOF sensor uses one SPOF and two FPOFs to detect fuel level change based on the optical signal output from the two FPOFs. The sensor design uses large-diameter (core and cladding), lightweight, low-cost and high-durability plastic optical fiber, which is very desirable for airplane installation.

The present disclosure relates to an apparatus and method for liquid level detection. The method may include providing a circuit board including a plurality of horizontally mounted emitter/receiver pairs arranged vertically along the circuit board within a liquid containment area. The method may further include determining, using one or more processors associated with the circuit board, if liquid is present between each of the plurality of emitter/receiver pairs based upon, at least in part, data received from one or more of the plurality of emitter/receiver pairs.

Systems and methods that use a differential spectral liquid level sensor to measure the level of liquid in a reservoir (e.g., a fuel tank or other storage container). The use of a differential spectral liquid level sensor solves the problem of common-mode intensity variations (i.e., intensity variations not due to the level of the liquid) by having two different wavelengths propagate through the same optical path but have different spectral attenuations in the liquid. By determining the ratio of the received optical powers, common-mode intensity variations can be neutralized, thereby enhancing the accuracy of the received power reading and the resulting liquid level indication.

The present invention relates to a field device adapted to determine a process parameter value related to a tank, the field device comprising a terminal block with: a first interface configured to connect to two wires of a loop; a first electrical conductor and a second electrical conductor for connecting the first interface with field device electronics, the second electrical conductor having a voltage drop generating element; a first power supply conductor connected to said second electrical conductor upstream of the voltage drop generating element and a second power supply conductor connected to said second electrical conductor downstream of the voltage drop generating element; and a second, auxiliary interface adapted for wired connection to an external device and configured at least for communication with said external device, wherein the second auxiliary interface comprises a communications connector which is galvanically isolated from the field device electronics.