1·Fuse potassium dichromate (19) in a porcelain crucible.
在瓷坩埚中熔化重铬酸钾(19)。
2·A porcelain crucible was heated to a dull red color, placed on the test material, and allowed to cool to ambient temperature.
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。
3·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。