Engineering360: "LevelGuard Pump Switch Passes 3.5 Million Cycles in Test"

What the world really needs is a differential reasonably clear, low to mid-viscosity liquid pressure switch that will perform similarly over a user-selectable range of 10-1000 kPa, and cost less than $50. OK, I will go as high as $75, if it will handle seawater at a temperature range of 0-100 degrees C.