A level sensor is one example of a ‘low-tech’ sensor.

The water level sensor (12) comprises a sensor box (15).

The container (3) is provided with an upper level sensor (4) and a lower level sensor (18) and a temperature sensor (11).

A liquid level sensing system including a receptacle and a liquid level sensor.

The apparatus comprises a level sensor, a pressure sensor and a computer.

Each sensor (2, 4, 6, 8) may be a fluid level sensor.

The water-level sensor is disposable.

A fluid level sensor assembly comprises a sensor mounted to a sensor housing.

The level sensor provides a parameter representative of a level of the liquid.

The first level sensor may be configured to generate first level sensor information based on sensing an event.

Fluid level sensor.

The central processing unit (CPU) is connected to a presence sensor (S1), with a level sensor (S2), and can be connected to the level sensor of the refresher (S3).

The wireless sensor device comprises a light level sensor and an energy accumulator for providing power to the wireless sensor device.

As the fluid level falls past the upper sensor a second time level is measured, with both time intervals being terminated as the level falls to the lower level sensor.

Level sensing means measures the photodetection level of the laser beam at each photodetector.