If your Vernier Barometer readings do not agree with the local weather reports, it is because you are looking at two different kinds of readings.

“Station pressure” is the actual pressure at your site, or station. This is the pressure a mercury barometer would report. It can be useful for making calculations involving gas laws in chemistry courses. This is the pressure that your Vernier Barometer is calibrated to read when new.

“Barometric pressure,” also referred to as “sea-level pressure,” is the pressure reported after the station pressure has been adjusted to its estimated equivalent at sea level. This adjustment is made based on the elevation of the Barometer; if at sea level, the station pressure and barometric pressure would be the same. But the higher in elevation, the greater the difference between the two. Meteorologists, including television and radio station forecasters, usually report barometric pressure rather than station pressure because it takes elevation out of the equation for weather forecasts.

Because we don’t know at what elevation your Barometer will be used, the Vernier Barometer is shipped reading station pressure. If you want your Vernier Barometer to read barometric pressure instead of station pressure, perform and store a single-point calibration using a reported pressure at your elevation.