Test A: porcelain Crucible ? A porcelain crucible was heated to a dull red color, placed on the test material, and allowed to cool to ambient temperature.

• 测试A：陶瓷坩埚。将置于所测试材料表面的陶瓷坩埚，加热至暗红色然后让其冷却，温度降至室温。