In multiple magnetic sensors, for a correlation function between a magnetic field applied from a magnet and a value of the magnetic field detected by the magnetic sensor at a first temperature, the value detected by the magnetic sensor when the magnetic field applied from the magnet is 0 is set to be a first offset value. For a correlation function between a magnetic field applied from the magnet and a value of the magnetic field detected by the magnetic sensor at a second temperature, the value detected by the magnetic sensor when the magnetic field applied from the magnet is 0 is set to be a second offset value. The second temperature is higher than the first temperature. A values of applied magnetic fields detected by first and second magnetic sensors are opposite in polarity.

A system for monitoring a state, for example a filling state of a container, with a first sensor which in operation produces a measured value, and a second sensor which in operation produces a second, discrete measured value. The first measured value and the second measured value are forwarded to an evaluation unit via a common line.

A system for monitoring a state, for example a filling state of a container, with a first sensor which in operation produces a measured value, and a second sensor which in operation produces a second, discrete measured value. The first measured value and the second measured value are forwarded to an evaluation unit via a common line.

Methods, apparatuses, and storage mediums are provided for detecting water shortage for a humidifier. The method includes: obtaining a water level parameter of a water tank; determining a water level state of the water tank according to the water level parameter. When the water level state of the water tank is a water shortage state, energizing a valve connected to a water box so that water can be added to the water tank through the valve. A number of times of energizing the valve is recorded. When the number of times of energizing the valve exceeds a first preset number of times as well as when the water level state of the water tank determined every time after energization of the valve is the water shortage state, confirming that the water box is short of water.

Methods, apparatuses, and storage mediums are provided for detecting water shortage for a humidifier. The method includes: obtaining a water level parameter of a water tank; determining a water level state of the water tank according to the water level parameter. When the water level state of the water tank is a water shortage state, energizing a valve connected to a water box so that water can be added to the water tank through the valve. A number of times of energizing the valve is recorded. When the number of times of energizing the valve exceeds a first preset number of times as well as when the water level state of the water tank determined every time after energization of the valve is the water shortage state, confirming that the water box is short of water.

A liquid level detection device includes a float that ascends and descends following a liquid level, a magnet attached to the float, a guide that guides the float to ascend and descend, magnetic sensors attached to the guide and sensing a magnetic flux density varying in response to a position assumed by the magnet as the magnet ascends/descends and outputting an electrical signal corresponding to the magnetic flux density, and a detection circuit that detects a position of the float based on electrical signals respectively output from the magnetic sensors. The detection circuit detects the position of the float based on electrical signals output from two adjacent ones of the magnetic sensors.

A liquid level detection device includes a float that ascends and descends following a liquid level, a magnet attached to the float, a guide that guides the float to ascend and descend, magnetic sensors attached to the guide and sensing a magnetic flux density varying in response to a position assumed by the magnet as the magnet ascends/descends and outputting an electrical signal corresponding to the magnetic flux density, and a detection circuit that detects a position of the float based on electrical signals respectively output from the magnetic sensors. The detection circuit detects the position of the float based on electrical signals output from two adjacent ones of the magnetic sensors.

Disclosed herein is a telemetric fitting for a liquid-level gauge, the telemetric fitting being configured to derive liquid-level information from the liquid-level gauge when attached thereto and wirelessly transmit at radio frequencies the liquid-level information.

Disclosed herein is a telemetric fitting for a liquid-level gauge, the telemetric fitting being configured to derive liquid-level information from the liquid-level gauge when attached thereto and wirelessly transmit at radio frequencies the liquid-level information.

Provided is a liquid level alarm device for a water filter including an alarm assembly and a liquid level detecting device. The liquid level detecting device is electrically connected to the alarm assembly and arranged in a water tank of the water filter. The alarm assembly is arranged on the water tank. The liquid level detecting device is configured to, in condition that a liquid level in the water tank rises to a preset height, send a liquid level warning signal to drive the alarm assembly to send an alarm signal. By arranging the liquid level detecting device in the water tank of the water filter, the liquid level in the water tank is detected by the liquid level detecting device. When the liquid level in the water tank of the water filter reaches the preset height, the liquid level detecting device sends a driving signal to drive the alarm assembly to send an audible and visual alarm signal. When seeing or hearing the audible and visual alarm signal, the user can know that the filter element of the water filter is blocked and fails to operate normally.