Ordinary coffee machines usually have at least one liquid level sensor to detect the water level of the tank. The liquid level sensor will give the signal according to the change of the liquid level, and the coffee machine can realize the function of water shortage protection or automatic water injection function.

And some coffee machines do not have liquid level sensors. This type of coffee machine usually has partially transparent water tanks, and smaller areas allow the user to see the water level. However, this makes the water tank partially transparent and more complicated. The tanks must be treated twice before being made partially transparent, but this is not possible for tanks of certain materials. Moreover, because only a small part is transparent, once there is only a small amount of water in the tank and the customer forgets to add water, it is inevitable that half of the coffee has no water in the use process, affecting the user experience.

The external water tank of some coffee machines is well designed, which will make the appearance of the coffee machine not very beautiful, and the appearance is one of the factors for users to choose and purchase the product. If the tank is externally designed, manually check the water level and then add or stop the water. If the user forgets to check the water level before use, it may cause the machine to dry and cause short circuit and tank overflow.

The level sensor can be used to accurately and quickly detect the level, and the control circuit can remind the user to add water or control the power off protection device. The non-contact liquid level sensor uses the principle of capacitor to detect the liquid level state, and judges the high and low liquid levels according to the output signal of water and no water. At the same time, it also has the characteristics of high accuracy, high reliability and high repeatability. Therefore, the capacitive liquid level sensor can be used in the coffee machine and the water level detection accuracy can be controlled at ± 1mm.

The level sensor can be used to accurately and quickly detect the level, and the control circuit can remind the user to add water or control the power off protection device. The non-contact liquid level sensor uses the principle of capacitor to detect the liquid level state, and judges the high and low liquid levels according to the output signal of water and no water. At the same time, it also has the characteristics of high accuracy, high reliability and high repeatability. Therefore, the capacitive liquid level sensor can be used in the coffee machine and the water level detection accuracy can be controlled at ± 1mm.