Collecting Materials & Supplies

Looking for materials (air/gases/liquids) that deflect easily to changes in air pressure.

Also looking at various liquids as to their various properties of:

Density

Viscosity

Conductivity

-because water is 13.6 x lighter than mercury it will climb that much faster and further than mercury as a barometer. As a result, it will reflect a more architectural scale.

-tubes ranging through several floors, was well as at several different levels and altitudes.

-the material needs to have a greater density than water, but is less viscous, and if is to become a switch, or pot then it needs to be conductive.

-need to determine if as the pressure along the tube changes does the relative capacitance along the tube change?

-water conductivity - electrolyte solution - can conduct electricity

(ion = wanderer in Greek)

-table salt NaCl electrolyte

Liquids Denser that Water Temp t (C) Density p (kg/m3)

water 4 1000

sulphuric acid (95% onc.) 20 1839

mercury 25 13590

iodine 25 4927

chloride 25 1560

bromine 25 3120

Conductivity

-iodine would make a great choice as a pressure sensitive material except that it is not conductive.

-the conductivity of water increase as the NaCl ratio increases.

(source www.horiba.com)

Salinity (density of salt in salt water) and conductivity. Liquid temperature 25 degrees C

NaCl density (w/v)% Conductivity (mS/cm)

0.1 2.0

0.5 9.2

1.0 17.6

1.5 25.6

2.0 33.0

The more Na+ and Cl- contained in water the more electricity is carried, and the higher the conductivity. Therefore if we know the conductivity of a sample of salt water, we can calculate just how salty the water is.