A dip tube is a long, thin tube inserted into a liquid storage tank to measure the level of the liquid. It is typically made of metal or plastic and has a small hole at the bottom to allow the liquid to enter. The dip tube is marked with graduations that indicate the liquid level in the tank.
Checking the dip tube is an important part of maintaining a liquid storage tank. It allows you to monitor the liquid level and ensure that the tank is not overfilled or underfilled. Overfilling the tank can lead to spills and leaks, while underfilling the tank can lead to equipment damage.