: Most Airguide barometers are designed for indoor use. Because air pressure is the same inside and outside, you don't need to mount it outdoors.

| Pressure (inHg) | Needle Movement | Forecast | | :--- | :--- | :--- | | Above 30.20 | Steady or rising | Fair, dry conditions | | 29.80 – 30.20 | Steady | Variable, no immediate change | | Below 29.80 | Falling fast (more than 0.10 in 3 hours) | Rain or snow within 12-24 hours | | Below 29.50 | Rapid fall | Storm conditions, high winds |

An original manual often includes care instructions that extend the instrument’s life by decades:

Your Airguide may someday stick, drift, or grow quiet. This is not failure. It is character. A gentle cleaning, a re-calibration against a known pressure (your local airport’s altimeter setting will do), and it will speak again.

The manual will also explain how to read the pressure readings, including how to interpret the different dials, pointers, and digital displays.

Welcome to a quieter kind of weather forecast. One that doesn’t involve a smartphone, a satellite, or a smiling TV anchor.

: Tap the glass lightly as you adjust to ensure the needle doesn't "stick".

Before diving into the manual, it helps to understand the manufacturer. The Airguide Instrument Company, based in Chicago, IL, was a prolific producer of weather instruments from the 1930s through the early 2000s. They were best known for their: