This prototype is essentially a pump. The pump is essential to create water flow for the saturometer to work. I made valves by using the diaphragms from an old respirator, and designing a new retainer ring modeled off of the one in the respirator. I made the pump chamber from silicone, using a balloon as the form. When squeezed, it pumps a small amount of water (or air) through it. In the future, I want to use a 3D printed form for the bladder.