A vacuum insulated refrigerator cabinet comprises an evacuation system for evacuating an insulation space of the cabinet when pressure inside such space is higher than a predetermined value. It comprises a sensor device having an insulation reference element located on one side of said insulation space and temperature sensors for assessing the differences of temperature across the insulation space) and across the insulation reference element, such sensor device being suitable for providing the evacuation system with a signal related to the ratio of the above differences of temperature.