Calibration Barometer

An idea from Joni (flashead) to shoot my own mercury calibration barometer. I had to show it in 3 pieces as the unit is a meter long. These are called standards barometers.

First you adjust the knob on the bottom so that the pin dimples the mercury pool (right side). Then you slide the center knob down till it lines up with the top of the mercury meniscus (left side). From the closest matching mark on the scale read the amount. Third step is read the temperature on the thermometer (center). Final step is to perform a calculation using your read value correcting for temperature and altitude. Your result is a fully corrected barometric pressure reading to sea level.

Here is a full length shot of the whole unit.

Kind of cool blown up...