In the context of the air meter, what does the term "meniscus" refer to?

The term "meniscus" specifically refers to the curve of the liquid level observed in a container, such as a graduated cylinder or an air meter. When a liquid is poured into a vertical container, the surface tension between the liquid and the container's walls causes the liquid to curve, forming a concave shape at the surface. This curve is crucial for accurately reading measurements, as the measurement should always be taken from the bottom of the meniscus to ensure precision. In the context of the air meter, understanding the meniscus helps in accurate assessment of the water level, which is vital for determining the correct amount of air in the mix.