You are working as an engineer on a project that involved being able to accurately measure the fluid level change in a large outdoor holding tank. The fluid level rises and falls about twice every second and is measured using a sensor that returns a voltage to represent the fluid height.

You are having difficulty because there are a lot of ripples on the surface that are affecting your height measurement. After some calculation, you find that the ripples are rising and falling 20 times a second or faster.

Design a simple circuit that you can connect to your fluid level voltage meter so that you can accurately detect the rise and fall of the fluid without detecting much change due to the ripples. Draw the circuit showing component values and connections for the input and output.