This apparatus is designed to demonstrate to students that volume of
air enclosed in the column is clearly visible to students. A wide bore glass tube is mounted vertically in front of
a scale
graduated 0-60 cm. Zero corresponds to the inside of the closed top end of the tube. Air is confined in the
tube by a
coloured oil contained in a metal container fitted with a Bourden type gauge. A tap is fitted to the side
of the metal
container, for the air inlet tube from the pump. As the pressure in the oil container is increased, oil
is forced into the
glass tube and volume of contained air and its actual total pressure are directly indicated. The
tube is of extra strong
glass having very large safety overload margin. As a further precaution, a safety plastic
screen is secured over the front.
Overall ht. 690 mm approx. Supplied complete with oil.
