A fluid reservoir (101) includes a number of electrode pairs disposed within the fluid reservoir. Each of the electrode pairs includes a number of sensing electrodes (103), and a number of electrical traces (105) wherein the sensing electrodes are coupled to a respective one of the electrical traces. The fluid reservoir also includes a common electrode (104) electrically coupled to a voltage source (106). A number of properties of a fluid (110) within the fluid reservoir are detected by applying a voltage between the sensing electrodes in an electrode pair, and a level of the fluid within the fluid reservoir is detected by applying a voltage between the electrodes and the common electrode. A multiplexer (102) may be used to selectively couple the sensing electrodes (103) to a processing device (108). The fluid reservoir may be a printing fluid container.

A sensing structure in an example may include at least three electrodes along an interior surface of a reservoir from a top portion of the reservoir to a bottom portion of the reservoir wherein at least one of the electrodes is closer to at least another electrode at the top portion of the reservoir than at the bottom portion of the reservoir.

A probe unit having a coaxial structure and including a probe electrode, a guard electrode and a contacting module arranged on a section of the probe electrode, which contacting module including an insulating sleeve, a flexible circuit board with a first conduction path for the electrical contacting of the probe electrode and a second conduction path for the electrical contacting of the guard electrode, and a module housing, wherein a first contact plate is provided that electrically contacts the first conduction path, the module housing including a second contact plate that electrically contacts the second conduction path, wherein the module housing has a pot-shaped geometry with a cylindrical wall, which wall substantially surrounds, protects and/or electromagnetically shields at least the probe electrode in the region in which the contacting module is arranged, at least a part of the insulating sleeve, and at least sections of the circuit board.

A combination temperature and low water sensor includes a body configured to penetrate the wall of a hydronic furnace. A detection tip is attached to the body and extends into the furnace when the temperature sensor penetrates the wall. The detection tip is electrically conductive and defines a tip interior volume. A temperature sensor is disposed within the interior volume of the detection tip. Both the detection tip and the temperature sensor are configured for electrical connection to a furnace control system.

A wireless remote monitoring system for biomedical fluid management that uses one or more sensors to detect changes in fluid or air in any container attached to a patient in order to monitor pre-surgical or post-surgical progress or complications. The sensors may be configured to monitor any type of container used to collect fluid or air from the human body, to transmit the sensor signals wirelessly to any number of devices including, but not limited to, cell phones or devices which in turn can send data to a functional repository where it can be analyzed and potentially acted upon by either a central or distributed network of providers.

A self-cleaning sensor to determine a level of a liquid includes a tube with an interior coating and a plurality of horizontally aligned, electrically isolated, electrical contacts. The self-cleaning sensor includes the plurality of horizontally aligned, electrically isolated, electrical contacts that each terminate in an outer surface of an interior wall of the tube and are electrically connected to one or more electrical devices in a cap residing on the tube. Additionally, the self-cleaning sensor includes a float that is composed of a low density, low dielectric constant material buoyant in one or more liquids to be measured where each horizontal dimension of the float corresponds to each horizontal dimension of the tube.

A pump assembly with at least one liquid space (32) in an interior. The liquid space (32) contains a liquid or is configured for receiving a liquid. A sensor (34, 42) is arranged in the liquid space (32), which sensor is configured to detect at least one material property of the liquid located in the liquid space (32). A filter element (44) is arranged in the interior of the liquid space (32) such that the filter element (44) shields the sensor (34, 42) with respect to the surrounding liquid space (32), the filter element (44) being permeable to the liquid. A method for controlling a pump assembly is also provided.

An example printing cartridge includes a fluid container, a sensing die including a plurality of sensing locations in thermal contact with the fluid container, and a voltage comparator to output time-based information by comparing a sensed voltage generated at a selected sensing location of the plurality of sensing locations to a threshold voltage, the time-based information representative of whether a fluid is present at the sensing location.

A fuel filter may include a housing and a filter element positioned within the housing. A water collection chamber may be defined in the housing and may be constructed and arranged to collect water separated from a fuel. A water level sensor may be positioned within the water collection chamber. The water level sensor may be constructed and arranged to detect a water level in the water collection chamber. The water level sensor may include an electrically conductive plastic first terminal.

Systems and methods for providing remote notifications upon the detection of certain conditions. In one embodiment, a device comprising a housing, a power unit, a liquid sensor, and a communications unit detects the presence of a liquid and initiates an alert notification that is transmitted to a remote device.