Hydrometer Beaums

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.

A glass tube of 6mm bore is enclosed in an enamelled and lacquered brass case, mounted on a polished wooden board with plates for fixing on wall. Open plate reflectors, ring and screws for vertical adjustments. A dual scale graduated in 25 to 32 inches and 640 to 810mm is read by verniers moving by rack and pinion, reading to 0.002 inch and 0.1mm are enclosed in a glass cylinder. A glass cistern at the lower end of barometer is provided with an ivory point to adjust the level of mercury. A thermometer -10 to 50C is provided on the wooden board. Supplied without mercury and glass case.