Abstract: A thermocouple jacket monitor is disclosed. The thermocouple monitor is constructed utilizing an inner jacket and an outer jacket with a replaceable conductive metal strip sandwiched between the inner jacket and a central insulator housing the thermocouple junctions. The conductive metal strip is connected to an alarm circuit in the thermocouple head. When the outer and inner jackets are corroded away by a molten material, such as molten glass, exposing the conductive metal strip to the molten material, the alarm such as a light on the thermocouple head, or the control panel or both, is lit notifying the operator that the thermocouple is damaged and needs to be replaced. If a two-way continuity alarm circuit is utilized, a second alarm light is activated when any portion of the conductive metal strip is corroded to the extent of being separated.