Desiccation is the easiest clinical function to achieve because any wave-form can be used to desiccate, i.e. cut or coagulate wave-forms This is because any wave-form causes the contents to heat through the resistance given by the cell to the electrosurgery current. This is very similar to an electric fire where a current is passed through a wire so that its resistance causes it to heat.

The cells of the body behave likewise and the water within the cells becomes hot enough to cause desiccation to occur through the water being driven slowly out through the cell wall.

With desiccation, it is important for the electrode to be kept in contact with the tissue so that sparking does not occur. The amount of power on the dial setting required to effect any desiccation will depend upon the size of the electrode contact with the tissue, i.e. a large ball electrode will require a higher output setting than a small electrode. Thus in technical terms the current density at the contact site has to be high enough to cause desiccation.

The bipolar output is for pure desiccation where sparking is not required and to the contrary inhibits the technique of bipolar surgery. The bipolar output is designed to desiccate wet tissue grasped by the forceps. This has a different electrical characteristic to that of monopolar surgery, as the tissue being less in mass, has a lower electrical resistance.

The monopolar output is for cutting and fulguration. Since sparking is part of the technique, it is important that desiccation is achieved at lower power settings using the CUT, BLEND or COAGULATION output modes with the electrode in contact with the patient.