G. Gerlach barograph

A barograph is a device for measuring atmospheric pressure, which enables mechanically recording the results obtained in the form of a chart called a barogram. The main pressure measurement component in the presented barograph is the so-called aneroid, i.e. a can with a needle attached to it. The lowered pressure inside the can allows it to deform under the influence of the surrounding atmospheric pressure, which results in movement of the needle. The rotating drum of the barograph with paper tape on it, on which a pen is moving, enables recording of data. The presented instrument was made in Warsaw in the 1930s. The establishment operated from 1816 until World War II and it specialised in the production of surveying instruments such as theodolites, levellers, range finders, steel squares and topographic tables. Manufacturer: Specjalna Fabryka Instrumentów Geodezyjnych i Rysunkowych G. Gerlach, 1930s Inv. No.: MIM 1720/XI-137 Model prepared on the basis of photogrammetric measurements Licence: CC BY-NC-SA