Aneroid Barometer Adjustment
Barometers are essential tools for forecasting weather. Without an accurate adjustment, inaccurate data will produce misleading results. When you first get a new aneroid barometer, follow these important procedures:
Make the Readings
The key to understanding any barometric reading is measuring the relative change. The center knob on front of the analog barometer lets you do just that. Use that knob to move the inside hand over the barometer's current setting. Using this large hand as a reference point, your aneroid barometer is ready to help predict weather as the small hand moves.
Periodically check if the reading on your aneroid barometer matches the broadcast reading. Over time, springs in the aneroid barometer mechanism slacken. Frequent adjustment tunes the device back to accuracy.
Aneroid barometer readings make pretty accurate weather forecasts for a 24 hour span.
In general, if the aneroid barometer is not moving, the weather will stay the same. Of course there are many exceptions. But that's what makes weather watching so interesting.