This device consists of a 36" / 90cm plastic cylinder that is capped on both ends with a rubber stopper. The stopper on one end of the tube has a 1/4 NPT ball valve fitting for air evacuation. A small vacuum pump is required. This device comes with a brass disc (simulates penny) and a small feather (guinea feather). When the tube is inverted under normal atmospheric pressure, students will see that the penny falls at a faster rate than the feather because of air resistance. When the tube is connected to a vacuum pump and the air removed, a vacuum is created. After the air is evacuated, and the tube is inverted, the penny and the feather will fall at the same rate. Click on the Technical Specs
tab above for additional information.
Length: 36" / 90cm Tube ID: 2 - 1/16" / 52mm Shutoff Valve Type: Swing/Ball Valve inlet Diameter: 1/4 NPT