Abstract: An apparatus and method useful in a test and measurement instrument for selecting a particular television field for display, determines the television system standard from the input signal, uses the standard selection to determine the time for one field, and multiplies the field rate by an operator-supplied number of fields to calculate the required holdoff time. The subject invention relieves the operator from turning the holdoff control multiple times, and also relieves the operator from having to calculate the time delays for any of one to seven fields of holdoff (in the case of a PAL signal).

Abstract: Iontophoresis apparatus for applying local anesthetics to selected locations of animal bodies, particularly to the eardrum, comprises an electric circuit providing a source of direct current of constant and predetermined magnitude. Connected into the electric circuit are a first electrode adapted for placement in a quantity of ionized liquid anesthetic and a second electrode adapted for placement in contact with the body in a spaced location. A current adjustment circuit adjusts the current to selected values. Application of a constant current which may be progressively increased or diminished at the will of the operator provides effective iontophoretic action resulting in efficient anesthetization of the body area without adverse effects.