Barometric Elevations

Powell scanned from the rims a country even more wild and desolate than the canyon through which the boats felt their careful way. A great plateau was cut completely in two by the river. From a tower which he climbed he looked across the high pine forests clothing the summits, and across the dozens of canyons heading in mid-plateau and deepening toward their confluence with the Green or with the White and Uinta to the north. But he could see little that told him what lay to the south, only the widening gray and brown lips of canyons cutting toward unknown junctions. He took barometric measurements of the depth of strata, height of walls, fall of river... (1).

In this experiment you will use differences in the barometric pressure to measure the elevation difference between a USGS benchmark on the Montana Tech campus and another benchmark on the top of Big Butte.  You will be responsible for developing the theory that links elevation with barometric pressure.  The theoretical link between pressure and elevation is typically developed in most physical chemistry textbooks and I leave it up to you to explore these references.  You are also responsible for constructing the experimental apparatus needed to obtain the data necessary to apply the theory to calculating the required elevation difference.  The theoretical background, materials and chemicals, experimental procedure, data, calculations, and references for this experiment are all described in a little more detail in the MS Word document Barometric Elevations.

Data

You will have to construct, reference, and calibrate your own experimental apparatus in this experiment, principally a water barometer. 

Safety

Since the barometer you construct will use water as its working fluid, there are no particular safety precautions that you need to be aware in this lab.  If a Hg barometer is used to reference and/or calibrate your water barometer, you should avoid exposure to toxic Hg vapors.