Barograph

A barograph is a type of meteorological instrument used to measure and record atmospheric pressure over time. It consists of a sealed chamber containing a partially evacuated drum or cylinder, which is connected to a pen or stylus. The pen is attached to a lever mechanism that moves up and down in response to changes in atmospheric pressure.

As the atmospheric pressure changes, the lever mechanism moves the pen, which in turn creates a trace or line on a rotating drum or chart. This trace represents the variations in atmospheric pressure over a specific period of time, typically 24 hours. The resulting chart is known as a barogram.

Barographs are commonly used in meteorology and weather forecasting to monitor changes in atmospheric pressure, which can provide valuable information about weather patterns and trends. They are often found in weather stations, research facilities, and observatories.

In the supply class Meteorological Instruments And Apparatus, barographs are categorized as instruments used specifically for measuring and recording atmospheric pressure. They fall under the broader supply group of Instruments And Laboratory Equipment, which includes various instruments and equipment used in scientific research, analysis, and experimentation.