Capacitance level sensor

grabcad

Capacitance level sensor measures capacitance between tube and inner rod which changes when fluid level changes. Capacitance can be calculated using simple circuit which measures how long it takes capacitor to reach certain voltage. Design uses standard size, off-the-shelf components (rod, tube, bolts) and design elements which reduces part count. Tube and rod length can be easily changed based on the measuring range. Tube and inner rod are separated by polystyrene parts. Plastic parts screw to both sides of the rod so no nuts are needed. This also keeps tension on the rod so the distance between tube and rod can't change which keeps the sensor accurate. All the plastic parts can be manufactured using injection molding. Sensor connects to the tank using national pipe thread which allows easy install and replacement.