Aneroid Barometer does not Change
- It is highly advisable to lightly tap the glass near the center brass knob with your fingers before taking a barometer reading. The light tap will overcome any friction that may affect accurate hand readings, especially during periods of slow atmospheric changes. The Coast Guard has informed us that tapping the barometer is even required on the most expensive aneroid barometers, because the mechanism is made deliberately “stiff”.
- Make sure you have calibrated the barometer to match the local airport. There is a discussion here:
- If you live at high altitude, your barometer may be out of range (reads low all of the time).Since barometric pressure is significantly affected by altitude (and to a lesser extent, changes in weather), the barometer must be calibrated to sea-level to offset altitude effects.If your altitude exceeds the measurement range of the sensor mechanism, the barometer can not be adjusted to compensate for your altitude effects. Most sea-level barometers operate up to 3,000′. You will need to purchase a barometer that is designed for higher altitude conditions.