A transparent, graduated syringe is attached to a pressure gauge so that one can show the relationship between pressure and volume at constant temperature for air.

Alternatively, the pressure gauge may be connected to a hollow metal ball that can be cooled with ice water to show the relationship between pressure and temperature at constant volume. By extrapolating a line plot of pressure versus temperature to zero pressure, one may deduce absolute zero.

P1

PIRA DCS 4E20.20