The main advantage of the vaporizers over other smoke generated products is the direct delivery of the vapors into the blood passing through lungs and hence helping in respiration, generating the pharmacological effect. Vaporizers are also useful in the process of titration in which the desired level has to be selected so that patient may receive the right dosage of the vapors. Vaporizers which are precise in nature are using the electric heating element. This type of heating element is mostly used in the thermostats.

The classification of the vaporizers can be done on the basis of the heating element or the substance which is used in them. Vaporizers heat the substance by the following process:

• With the thermal radiation.

• By the help of thermal conduction.

• By the process of convection.

In the method of conduction heating, the substance can be kept on the metal plate and is made to release the vapors or constituents. Conduction vapors are known to be the first category of the vapors which came into the marketplace and they are still in demand. While in the process of convection heating, the substance is not touched to the heating element. Hot air is passed and rapid heating is done which allows the releasing of the vapors.