How to set a barometer
To get the most accurate readings from your barometer it first needs to be ‘set’ so that it matches your local air pressure. This is easily done and only needs to be carried out once. Air pressure is measured in Millibars or Inches and to set your barometer all you need to do is to match its reading to your local air pressure. This calibration is done only once. It is easy to set your barometer
Step One Finding out your local air pressure is easy and can be done in a few simple ways. The friendly team at the Met Office love talking about the weather and are only too happy to tell you your local air pressure. Their number is 0870 900 0100 (local call rate), or +44 1392 885 680 from overseas.
Or you can do it from the many websites specialising in the weather reports such
as http://uk.weather.com (don’t add www.) Enter your postcode and you will get a weather report that shows the air pressure in mb (millibars). The BBC weather page is also an easy to use site too.
Step Two: Armed with that knowledge and the smallest flat head screwdriver you can find, adjust the screw on the back of the barometer; move it until the barometer needle reads the correct air pressure on the dial. (This is the lighter coloured needle). It is this easy to set your barometer, you can now rely upon the results.
You are now ready to predict the local weather!