The first ones were built in the 17th Century and used water or mercury.
Instead of using fluids, modern ones usually use a thin disk made of an alloy of beryllium and copper. This disk is attached to mechanical levers that make it easy to see and measure small contractions. The first ones were built in the 17th Century and used water or mercury. They were made by filling a large tube and inverting it in a larger container. Measurements were made by observing how high the column of liquid was. Name these devices used for measuring air pressure.
Instead of using fluids, modern ones usually use a thin disk made of an alloy of beryllium and copper.
Barometer(s) (or Barograph(s))