A sensor device includes a signal transmitting component configured to transmit a signal into a container engaged by the sensor device, wherein a frequency of the signal is selected to allow the signal to at least in part pass through a content fouling at least a portion of the signal transmitting component. The sensor device includes a processor configured to process a received reflected version of the transmitted signal to determine an identifier associated with an amount of content in the container engaged by the sensor device. The sensor device includes a wireless transmitter configured to transmit the identifier associated with the amount of content in the container.

This disclosure discusses a fluid property sensor, comprising an electrical circuit assembly (ECA) including an external interface coupled to a common interface bus; a fluid level sensor coupled to the common interface bus to indicate a fluid level and/or a pressure sensor coupled to the common interface bus to indicate a pressure event; and/or a driver circuit coupled to the common interface bus, configured to communicate characteristics of the fluid level sensor and the pressure sensor.

In one example a liquid level sensing device is described. The device includes a carrier and a liquid level sensing device disposed on the carrier. The liquid level sensing interface has an aspect ratio of at least 1:50. A number of liquid level sensing components are disposed on the liquid level sensing interface. The number of liquid level sensing components detect a liquid level in a liquid container. The liquid level sensing device also includes an electrical interconnect to output data collected from the number of liquid level sensing components.

In one example, a fluid property sensor includes a proximal elongated circuit (EC), a distal EC, and an external interface. The proximal EC has multiple point sensors distributed along its length. The distal EC is extended in the direction of the length from a distal end of the proximal EC and is electrically coupled from the distal end of the proximal EC to a proximal end of the distal EC. The proximal and distal ECs share a common interface bus. The external interface is electrically coupled to a proximal end of the proximal EC. The proximal EC, the distal EC, and the external interface are packaged together to form the fluid property sensor.

An example printing cartridge includes a sensing die including a plurality of sensing locations in thermal contact with a fluid container, an on-die controller to select a sensing location of the plurality of sensing locations to activate and to provide a variable threshold voltage, and a voltage comparator to compare a sensed voltage generated at a selected sensing location to the variable threshold voltage, and output time-based information based on the comparison, the time-based information representative of whether a fluid is present at a fluid level associated with the selected sensing location.

A method of detecting a level of printable fluid in a container includes, with at least one sensing location on a die in thermal contact with the printable fluid in the container, sensing a voltage of a capacitor over time as current from the capacitor leaks through a field effect transistor (FET). The FET and capacitor are associated with the sensing location. The method may further include, based on the voltage of the capacitor over time and a threshold voltage, determining whether the printable fluid is present at the at least one sensing location.

A hydration bladder fluid level detection system includes a pack having a hydration bladder removably secured therein; a display in communication with a power source and to attach to the pack, the display having; a high level indicator; and a low level indicator; a detector system, including a high level probe in communication with the high level indicator and to detect fluid at a first level in the hydration bladder; a low level probe in communication with the low level indicator and to detect fluid at a second level in the hydration bladder; and a power supply probe in communication with the power source and to complete an electrical circuit with the high level and low level probes as circuit components; fluid dropping below the first level deactivates the high level indicator by breaking a circuit leg running between the high level probe and the power supply probe; and fluid dropping below the second level deactivates the low level indicator by breaking a circuit leg between the low level probe and the power supply probe.

A kit for connecting to, and monitoring fill levels of a fluid storage tank includes a control module and primary and secondary sensor units. The control module is electronically connected to the primary sensor unit. The control module includes a circuit board with a microprocessor, memory unit, and transmitter. Each sensor unit includes a housing a seal attached to the housing around an opening thereof, attachment structure for attaching the housing to a wall of the tank, and an infrared sensor disposed in the housing proximate the opening. The primary sensor unit also includes a circuit board disposed within the housing, an ambient temperature sensor disposed in the housing, and a communications link for communicating with the control module. A method of monitoring a fluid level in a storage tank, and a system for monitoring and reporting fluid levels in a plurality of storage tanks, are also described.

An electronic liquid level gauge assembly includes an electronic display located in a housing connected to a tank. The display has first and second display portions for indicating liquid level condition. A first electronic sensor senses a change in magnetic field of a magnet associated with a liquid level transducer, with magnet rotation being proportional liquid level change. A processor determines a temperature-compensated liquid level condition by correlating the liquid level signal with temperature measurement of the liquid. A temperature-compensated vapor space can also be calculated based on tank information and properties of the liquid. Signals related to the temperature-compensated liquid level and vapor space are sent to the display and wirelessly transmitted to a smart phone or the like for remotely viewing the tank information. The smart phone also includes a special app for sending information, firmware updates, and display configuration data to the electronic gauge assembly.

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.