Warm liquid level indicating device

摘要

The device has appearance changing units whose state varies according to temperature of hot liquid without contribution of external energy. The appearance changing units are in thermal connection with a tank (C) containing the hot liquid. A heat transfer unit transfers heat between the tank and an insulating coating external wall (3) receiving the appearance changing units. The appearance changing units are partially covered by thermosensitive coating materials. The appearance changing units are provided with light indicators such as LEDs (2a-2d).