Aneroid barographs are used to measure and record the history of atmospheric pressure. The measuring element in the Fischer barographs is a set of 7 aneroid capsules, manufactured of a copper-beryllium alloy that essentially eliminates age-hardening, hysteresis, and elastic after effects that could otherwise degrade the accuracy. The influence of temperature on the set of aneroid capsules and the transmission system is compensated by use of bimetal components over the full measuring range and for temperatures between -30 to +40 °C (-22 to 104 °F). All contacts in the movements are jewelled to reduce friction.
For each model there is a choice of mechanical wind-up clockworks or quartz clockworks, which can be shifted in an instant for daily, weekly or monthly revolution. The actual periods are 25.6 hrs. 176 hrs., and 783 hr. The recording instruments are delivered complete with fibre pens and a year’s supply of recording charts.
Fischer instruments are unique in offering an option on each model with enhanced dampening for barograph use at sea.
