Does a barometer need setting?
If you want your barometer to give a reasonable approximation of the air pressure in your area, then you will need to set it. Find the nearest weather station to you that updates its pressure regularly online. Just after it gives the latest pressure, set your barometer. You will find a screw in the back that, when turned, adjusts the needle. After you have set the barometer, fine tune the setting after twenty four hours. Set your barometer to Mean Sea Level Pressure no matter where you are. For your use this will not matter and will allow you to compare pressures with the weather maps on TV etc. You should read your barometer at the same time each day and set the needle controlled by the knob on the front to cover the barometer needle at that time. You can then see whether the pressure is rising or falling during the day and whether it has risen or fallen in twenty four hours. There is a tide in the atmosphere called the diurnal variation of pressure which hits a maximum around 9am and
