A fluid level measurement system using a buoyant body includes a guide part installed in a direction perpendicular to the bottom surface of a fluid storage tank, and provided with a space in which a fluid can move therein; a buoyant body inserted into the guide part, and configured to float along the surface of the fluid inside the guide part; and a measurement part coupled to the top end of the guide part, and configured to measure the level of the surface of the fluid inside the fluid storage tank by transmitting a signal toward the buoyant body in the inner space of the guide part and then receiving a signal reflected from the buoyant body.

A fuel tank has a tank body, a post, a first resistor, and a second resistor, a floating body, a detecting part, and a guiding part. The tank body stores fuel. The post is formed in a tubular shape, is formed with a flow port, and is joined to the bottom wall and the top wall. The first resistor and the second resistor are provided inside the post and extend in a height direction. The floating body is provided with a conductor, is formed with guided parts, and floats on the fuel inside the post. The detecting part energizes the first resistor, the conductor, and the second resistor to detect the position of the floating body in the height direction. The guiding part is provided on the post to guide the guided parts in the height direction.

A device for monitoring the level or amount of a material within a container is provided. The device includes a detection mechanism that can be a direct detection mechanism or an indirect detection mechanism. When the detection mechanism senses an upper level of the substance in the container that is below a predetermined lower limit for the substance, the mechanism operates an alarm mechanism to emit an alarm to alert an individual to the low level of the substance within the container. The alarm can wirelessly communicate a salt level state to a wireless network or a device on a wireless network that can transmit the status through the Internet to any remote location. In one aspect, the alarm can be sent on a mesh network with a device that can transmit the status and other conditions through the Internet and to an application executing on a mobile device.

A fluid flow meter comprising a fluid pump to displace fluid with pumping strokes of one or more pumping stroke types wherein each of the one or more stroke types displaces a known volume of fluid, a sensor functionally associated with a fluid reservoir and adapted to generate a signal indicative of a fluid pumping condition within the fluid reservoir, which fluid reservoir is integral or functionally associated with the pump, and circuitry to trigger one or a sequence of strokes of the pump in response to a signal from the sensor.

A liquid level detecting device includes a sensor housing having a circular rotation recess, a circular holder which is fitted in the rotation recess and held rotatably by the sensor housing, a float arm, a float, a magnet, and a Hall element. The sensor housing has a lock groove and a pair of insertion holes. The holder has a pair of flanges which project in opposite directions from an outer circumferential surface of the holder and are engaged with the lock groove and prevented from coming off the rotation recess by setting the flanges opposed to the respective insertion holes, fitting the flanges into the rotation recess, and then rotating the flanges. The holder has a pair of support projections which come into contact with a bottom surface of the rotation recess.

A multi-probe sender may include a multi-probe having a reed switch arrangement in which reed switches form a level-sensitivity obtaining interval at which a value overlap is prevented in consideration of a resistance-value tolerance range, and having a probe layout forming an intersection interval at which value interference is prevented in consideration of an interval overlap of the reed switches.

A fuel tank has a tank body, a post, a first resistor, and a second resistor, a floating body, a detecting part, and a guiding part. The tank body stores fuel. The post is formed in a tubular shape, is formed with a flow port, and is joined to the bottom wall and the top wall. The first resistor and the second resistor are provided inside the post and extend in a height direction. The floating body is provided with a conductor, is formed with guided parts, and floats on the fuel inside the post. The detecting part energizes the first resistor, the conductor, and the second resistor to detect the position of the floating body in the height direction. The guiding part is provided on the post to guide the guided parts in the height direction.

A fluid flow meter comprising a fluid pump to displace fluid with pumping strokes of one or more pumping stroke types wherein each of the one or more stroke types displaces a known volume of fluid, a sensor functionally associated with a fluid reservoir and adapted to generate a signal indicative of a fluid pumping condition within the fluid reservoir, which fluid reservoir is integral or functionally associated with the pump, and circuitry to trigger one or a sequence of strokes of the pump in response to a signal from the sensor.

A fluid flow meter comprising a fluid pump to displace fluid with pumping strokes of one or more pumping stroke types wherein each of the one or more stroke types displaces a known volume of fluid, a sensor functionally associated with a fluid reservoir and adapted to generate a signal indicative of a fluid pumping condition within the fluid reservoir, which fluid reservoir is integral or functionally associated with the pump, and circuitry to trigger one or a sequence of strokes of the pump in response to a signal from the sensor.

A device for monitoring the level or amount of a material within a container is provided. The device includes a detection mechanism that can be a direct detection mechanism or an indirect detection mechanism. When the detection mechanism senses an upper level of the substance in the container that is below a predetermined lower limit for the substance, the mechanism operates an alarm mechanism to emit an alarm to alert an individual to the low level of the substance within the container. The alarm can wirelessly communicate a salt level state to a wireless network or a device on a wireless network that can transmit the status through the Internet to any remote location. In one aspect, the alarm can be sent on a mesh network with a device that can transmit the status and other conditions through the Internet and to an application executing on a mobile device.