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Barograph User’s Manual
5.4 Setting the correct local pressure
Your barograph will provide accurate pressures to within ± 0.7 hPa, but it is best to check the pres-
sure at first installation and adjust the pen position as needed. Local airports or weather services
offer pressure values as do some newspapers. There are also numerous convenient online sources
of local weather data. See in particular www.starpath.com/barometers which is set up specifically to
provide you with accurate local pressure worldwide, as well as elevation corrections.
Recall that most public sources of accurate pressure are corrected to sea level pressure, which will
be higher than the actual pressure at your instrument location unless you too are at sea level.
Thus to set your barograph to the correct local pressure, called
station pressure
, you must reduce the
reported sea level pressure for your location by an amount determined by the elevation of your loca-
tion plus the height of the instrument above ground level. See Appendix 1.
The Pressure adjustment screw is located above the measuring elements, as shown in Section 2.2.
There is a small lock screw on top of it that must be released before the adjustment and then gently
tightened once done.
Warning:
The pressure range of the barograph, from top to bottom of the chart, cannot
be changed without irreparably damaging the instrument. Therefore the pressure range
adjustment screws have been secured with lacquer and should not be adjusted.
5.5 Cleaning the Housing
The outside of the housing can be cleaned with a dampened washcloth and mild soap. Do not under
any circumstances use scrubbing agents or solvents.
Summary of Contents for 205M
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