Love Meter - Hand Boiler - Fun Science In The Palm Of Your Hand

The Love Meter, or hand boiler, demonstrates the ability of temperature to affect the pressure a substance exerts on the environment around it. If you increase the temperature of a substance, you will increase the pressure it exerts. This is best demonstrated in a closed container, like the clear glass container employed in the construction of the Love Meter. The Love Meter consists of two clear glass globes connected by a clear glass tube. The tube has usually been twisted into a bizarre shape like spirals, circles, or hearts. If you inspect the tube closely, you will notice that it extends below the surface of the liquid in the lower globe. The liquid in the hand boiler is what is termed a volitle liquid. The term volitle means that it evaporates at a very low temperature. The liquid used in these devices is usually chloromethane (or methyl chloride).

If you hold the Love Meter in the palm of your hand, the volitle liquid begins to evaporate under the gentle heat of your hand. Because a gas occupies more space than a liquid, and the gas has nowhere to go in the closed container, the gas now begins to exert pressure on the liquid under it. This pressure forces the liquid to enter the tube and flow upward into the upper tube. This will continue until almost all the liquid in the lower globe is in the upper tube.

The liquid in the upper tube now tries to run back into the lower globe, and is met by still expanding gas coming up from the lower globe. This ‘spouting’ causes the liquid to appear to be boiling, hence the name hand boiler.

The liquid will return to the lower globe by replacing the Love Meter to the table top and allowing the liquid to cool. It can be forced down by grasping the upper globe with the hand and heating the liquid there.

If you cool the upper globe with ice or cold air, you will get the same effect, as the temperature difference between the globes will cause a drop in pressure in the upper globe, causing the liquid to flow upward to the area of low pressure.

The Love Meter is a great toy and will be the source of amusement for almost anyone who sees it. Because it is made of glass, and is pretty fragile, it may not be suitable for young children.

The Love Meter sold by Plum Creek Marketing uses Ethyl Alcohol. The information below is for those who have other types.

Chloromethane is a toxic substance in high levels, so it is important to not ingest it. The amount found in the meter is minimal and not enough to be harmful. If the Love Meter breaks, wash it off your skin thoughorly. Chloromethane is found naturally in the atmosphere in very low concentrations. It is also found in chlorinated swimming pools, aerosol propellants, and in most drinking water. It is a natural substance, found normally in soils, water, and the air. It is given off when wood, charcoal, and other substances are burned. Chemical reactions in the ocean also release it.