| 摘要 |
<p>A heater comprising: a metal sheath; a heating element that is connected to the inner surface of the metal sheath at one end thereof; a center pole that is extending from an opening of the metal sheath to an interior of the metal sheath and directly or indirectly connected to the heating element; an insulating material that is packed in the interior of the metal sheath; and an elastic packing, wherein the opening of the metal sheath is closed by sealing of a gap between the metal sheath and the center pole with the elastic packing, and an axial length of a portion of the elastic packing, the portion is between the metal sheath and the center pole, is not smaller than 2.5 mm.</p> |
