Capacitivity fluids method
Capacitive liquid bitometers are a measuring device for measuring the height of liquids by changes in the capacity。
Its core idea is simple: when the medium around the sensor changes from air to liquid, right
Changes in electrical constants affect the capacity values. Through signal processing of capacitor changes
The height of the liquid level can be converted into readings in the form of voltage, frequency, number, etc. Here
The type sensors are typically made up of probes, electric shielding, insulation material and signal processing circuits
It's possible to contact both liquids and liquids without direct contact
Structure, with a degree of adaptability and application flexibility。
Basic physical principles and quantitative thinking
The basic expression for the capacitor is in the simplest parallel panel model:
Zero
Other
Zero
It's a vacuum communication constant
Here you go
It's the media's relative media constant
It's an overlapping area
It's the distance. The sensor's surrounding medium is not only uniform for the fluid
It's a medium with different media (liquid and air
Or multiple liquid mixtures, etc.) and therefore the actual equivalent electrical capacity depends on the degree of the fluid being passed sensor
The influence of the distribution of the medium around the device. A simple approximation allows the sensor to be detected
Seen in two mediums: at one end below or above the liquid level, the sensor is mainly surrounded by
Liquid encirclement. Consistency is close to liquid
εr lig
Above liquid level, surrounding
The medium is mostly air-oriented, and the electricity-composed medium constant is close to air
εr air
I don't know. If you put the liquid column high
Metric outline
To indicate that the equivalent capacitation can vary with the liquid level in a fraction or fraction
The model to describe。
In actual geometry, two lines of expression are common. The first is to pass it on
Sensors are seen as an electrical network that is co-generated with the outside environment, bearing in mind that changes in the fluid level make
Effective volume
The ratio of the medium in it has changed, thereby changing the total electrical capacity. The second is to pass it on
The sensor's conductor and the surrounding environment are considered to be a long bar-shaped condensation, with a change in the fluid height
Combine the distribution of the area or medium so as to change the capacity of the unit length, then by supersing, jack
Share the total electrical capacity. Either way, the core points to one conclusion: the higher the fluid, the higher it is
