초록 ▼

A capacitive liquid level detector for detecting a liquid level of a liquid in a receptacle, the liquid being conductive, the detector comprising: a capacitor with a first plate having a fixed size and being insulated from the liquid, and a second plate being formed by the liquid itself, its size be

A capacitive liquid level detector for detecting a liquid level of a liquid in a receptacle, the liquid being conductive, the detector comprising: a capacitor with a first plate having a fixed size and being insulated from the liquid, and a second plate being formed by the liquid itself, its size being variable depending on the liquid level inside said receptacle, wherein a thin film dielectric layer is formed on the surface of the first plate and located between the first plate and the second plate, the first plate with the thin film dielectric layer formed on its surface is arranged such that it covers an open part of the outer wall of the receptacle, the first plate with the thin film dielectric layer formed on its surface is attached to the receptacle by sealing means in order to seal the receptacle against liquid leakage.

대표청구항 ▼

What is claimed is: 1. A capacitive liquid level detector for detecting a liquid level of a liquid in a receptacle, the liquid being conductive, the detector comprising: a capacitor with a first plate having a fixed size and being insulated from the liquid, and a second plate being the liquid itself

What is claimed is: 1. A capacitive liquid level detector for detecting a liquid level of a liquid in a receptacle, the liquid being conductive, the detector comprising: a capacitor with a first plate having a fixed size and being insulated from the liquid, and a second plate being the liquid itself, the second plate having a size that varies depending on the liquid level inside the receptacle,wherein a thin film dielectric layer is on a surface of the first plate and located between the first plate and the second plate,a thin film passivation layer is between the dielectric layer and the second plate,the first plate having the thin film dielectric layer on its surface is arranged such that it covers an open part of an outer wall of the receptacle,the first plate having the thin film dielectric layer on its surface is attached to the receptacle by sealing means in order to seal the receptacle against liquid leakage, andthe thin film passivation layer is a sputtered SiO2, Si3N4 or SiOxNy layer, or a spincoated lacquer layer utilizing chemical resistant photo lithography lacquers.