Reservoir liquid level capacitive measuring sensor used e.g. in fuel tank of vehicle or steam cleaning equipment

摘要

The capacitive liquid level sensor (14) is designed to measure liquid level in a reservoir (12). The sensor is of the type which includes a capacitor (22) designed to be connected to a voltage source (16). The capacitor has two armatures (28,30) carried on two plates (32,34). These armatures are designed to be partially immersed into the liquid and the space (36) between them is partially filled with liquid. Two lateral parallel walls (38A,38B) connect at an upper part the two plates (32,34) on either side of the gap. Thus, the two lateral walls and the two plates form a rectangular section pipe arranged vertically in the reservoir. The distance separating the armatures is about 2 cms and the width of the plates is about 10 cms. The total length of the capacitor is 100 cms and the distance (36) between the two armatures is preferably between 1.5 and 3 mm.