Fischer 285M Mechanical Barograph

Fischer German 285M Mechanical Barograph in Mahogany Case Aneroid barograph used for the registration of atmospheric pressure. Measuring range 955 to 1055 hPa Accuracy ± 0.7 hPa Diagram graduation 1 hPa. The measuring element in our barographs is a set of 7 aneroid capsules with a diameter of 62 mm. This set is manufactured of a copper-beryllium alloy which by its remarkable elastic composition has been tried and tested best for many years.Age-hardening, hysteresis and elastic after effects don`t occur practically. The influence of temperature on the set of aneroid capsules and the transmission system is compensated by a bimetal about the whole measuring range and for temperatures between -30 and +40°C (-22 ... 104 °F). All the axles of the precision instrument are supported in jewels because of this the instruments have only got a minimum of idle friction. Parts of the measuring mechanism are made of polished brass. Mahogany colored wooden case: 13.58 x 6.69 x 7.09 inches (345 x 17