Why is necessary to check a liquid at eye level?

It is important to check a transparent liquid at eye level to ensure an accurate reading. When observing the level of liquid in a transparent vessel, surface tension may cause the liquid to curve upwards at the edges.

This phenomenon, known as meniscus, can create the appearance of a higher liquid level than the actual contents of the vessel. Reading the liquid level at eye level helps eliminate this visual distortion, providing a more precise and accurate measurement of the actual volume.

By aligning the line of sight parallel to the liquid surface, the meniscus effect is minimized and the liquid appears flat, allowing for a more accurate determination of the true liquid level.