Digital Jolly Bulb

Visually and effectively demonstrate the relationship between temperature and pressure. The Digital Jolly Bulb is the perfect alternative to the traditional bulb and analogue gauge; pressures can be read directly from the built in digital display and the apparatus is sensitive enough to register an increase in pressure when the bulb is held gently in the hand. By submerging the bulb in water at different temperatures the relationship between temperature and pressure may be demonstrated and the calibrated digital readout allows a quantitative investigation to be carried out if required.
For demonstration purposes' two 4mm sockets are provided to allow the pressure reading to be displayed on a large demonstration voltmeter (not supplied).
Supplied with 9V PP3 Battery and full instructions.