1. General Information
This manual contains important information about the function, start-up, and maintenance of Fischer
Barographs. Please review all of the information before initial use of the barograph. For the barograph
to function as intended, all instructions in this manual must be followed in detail. If the instructions are
not followed closely, operational malfunctions may occur.
2. About the Barographs
Fischer barographs record changes in atmospheric pressure over time. The measuring element
used is a 7-cell aneroid capsule set with a 62-mm diameter. They are constructed from a corrosion-
resistant copper-beryllium alloy whose excellent exibility has made it the best material for measur-
ing atmospheric pressure for the past 70 years. These aneroid capsules are essentiality immune to
hysteresis and elastic after-effects.
The effect of temperature changes on the measurement is compensated for with bimetal elements
over the full range of pressures for temperatures between -30° C (-22° F) and 40° C (104° F).
The elements of the precision movement are made of brass in various nishes, depending on the
model. All crucial axles use jeweled bearings for lowest possible residual friction. All materials used
are corrosion-resistant. The measuring element is enclosed within the fully ventilated housing and is
therefore protected from mechanical damages. Optional lockable housings are also available. Some
models employ an enhanced dampening movement for use at sea.
All standard barograph models have optional pressure ranges that are selected before purchase to
match the station elevation where they will be used, but the models with enhanced dampening are as-
sumed to be used at sea, so they come with a single xed pressure range for sea-level applications.
The barographs are equipped with either a mechanical or quartz clockwork that drives the rotation of
the recording drum.
For the quartz clockworks, the drum revolution can be easily set to a daily, weekly, or monthly cycle.
The corresponding time in hours would be 25.6 hr, 176 hr, and 783 hr respectively.
The mechanical clockworks can be changed between daily or weekly operation.
All models of barographs come with ber pens
and chart paper to last one year. The Captain
and Admiral models have a chart storage tray
built into them. The Captain model is accessed
from the end of the unit; the Admiral model from
the side.
Chart tray on Captain’s Choice model
