Should the electric kiln burner be sealed? Should the observation port of a high-temperature electric kiln with only one observation port be sealed with refractory bricks? When should it be sealed and

Should the electric kiln burner be sealed? Should the observation port of a high-temperature electric kiln with only one observation port be sealed with refractory bricks? When should it be sealed and opened? It should be sealed, but it can't. Seal the kiln when you open it. When the temperature reaches a certain level, the firebrick in the observation port can be removed to see if the temperature meets the requirements. Immediately after the observation, the refractory bricks are sealed, and this operation is repeated until the required sintering temperature or technical requirements are reached. The design of the observation port refractory brick is movable.