Edmund Barometer Tutor

Two Devices In One

Deliver precise and accurate readings of atmospheric pressure with this device as well as manipulate air pressure to simulate changes in atmospheric pressure. The squeeze bulb and hose allow you to manipulate the air pressure within the device, so you can directly observe how a barometer responds to and measures air pressure. Then you can use these measurements to make powerful predictions of the weather in your area. This barometer operates without liquid, but uses a thin metal diaphragm mechanism to measure the effect of atmospheric pressure. The unit is circular, constructed of two identical convoluted diaphragms sealed at their edges. When this capsule is completely evacuated of air, it will respond to pressure changes in the atmosphere.

Such changes proportionally affect the changes in the thickness of the capsule, which are magnified through levers, finally causing a needle to rotate over a circular scale. This scale is divided into equivalent "inches of mercury" and millibars. This action can be observed on the Barometer Tutor.