1. Do I need to calibrate the barometer after receiving it?<!--en-->Yes, once. The instrument is set to sea level by default. If you live up to approximately 800–900 meters above sea level, you can set the pointer yourself to match the current atmospheric pressure reported by a weather station or buienradar in your area. Do you live higher? Please indicate this in advance — we can calibrate the instrument for your location at an additional cost. 2. How does the mechanism work? A falling pattern means deteriorating weather is approaching; rising means clearing skies. 3. What does the second (trailing) pointer indicate?<!--en-->You set it yourself to the current reading. At the next reading, you can see at a glance how much the pressure has changed since then — the difference between the two pointers tells you more than the absolute number. 4. Does the barometer need a battery?<!--en-->No. The aneroid measurement works entirely mechanically: a membrane senses the air pressure, and the pointer displays it. No power, no maintenance. 5. Where is the best place to hang it?<!--en-->Indoors, out of direct sunlight, and not above a heat source — temperature fluctuations can make readings unstable. Air pressure is the same indoors and outdoors, so an interior wall is fine.