CABLE STRENGTH REDUCTION DETERMINATION METHOD AND HEAT RECEIVING TEMPERATURE HYSTERESIS DISPLAY STRUCTURE USED FOR THE METHOD

To discriminate whether or not the strength of a cable is lowered by the influence of a fire from an appearance of the cable which is exposed to a high temperature and then returned to a normal temperature.SOLUTION: Attached to a cable is a heat receiving hysteresis display part which extends in the length direction of the cable and maintains a second color regardless of the change of the heat receiving temperature after a first color at normal temperature is changed to the second color at a predetermined heat receiving temperature. After the cable is affected by a fire, whether the strength of the cable is reduced or not is determined based on the heat receiving temperature of the cable determined by the color of the heat receiving hysteresis display part.SELECTED DRAWING: Figure 1 【課題】高温に曝された後、常温に戻った状態のケーブルの外観から、火災の影響により強度が低下したかどうかを判別することを可能とする。【解決手段】ケーブルの長さ方向に延在し、常温における第一の色彩が所定の受熱温度で第二の色彩に変化した後、前記受熱温度の変化によらず前記第二の色彩が維持される受熱履歴表示部を前記ケーブルに付け、前記ケーブルが火災の影響を受けた後、前記受熱履歴表示部の色彩により判定される前記ケーブルの受熱温度に基づき、前記ケーブルの強度低下の有無を判定する。【選択図】図１