The large barograph 78b for precision measurements has twice the recording scale of the standard barograph 78a. A correspondingly larger number of aneroid cells guarantees measurement accuracy for a recording height of 1.5 mm for 1 hPa; the error limits are ±0.2 hPa.
Due to its high reading accuracy, the large barograph has found its way into aviation operations and many meteorological stations. It is preferred wherever a more precise determination of air pressure and the trend of air pressure is important.
For the barograph 78b, a vibrator 78v is available on request, which is inserted with 2 plug pins into the sockets arranged in the base plate.
It is operated with a 230V plug-in power supply and causes a barely noticeable vibration of the lever arrangement, which reduces bearing friction and thus increases the setting reliability and sensitivity of the recording.
The large barograph is only available in a precious wood case and is manufactured in three types that differ only in their altitudes.
No.
78b For altitudes from -50 to +725 m, relative to sea level, adjustable to 6 measuring ranges above 175 hPa
78b/2 For altitudes from 700 to 1850 m above sea level, adjustable to 6 measuring ranges above 205 hPa
78b/3 For altitudes from 1800 to 2700 m above sea level, adjustable to 4 measuring ranges above 165 hPa
The main features of the Great Barograph are:
network-independent and tamper-proof
wider recording drum (105 mm)
Pressure gauge with overload protection for transport up to 2700 m altitude
