| 摘要 |
PURPOSE:To reduce the amplitude of temperature of the central section of a heating box by oppositely disposing a cover for a heat sensible instrument to a heater and forming a long hole larger than the heat sensible instrument to a wall surface opposite to the cover. CONSTITUTION:The heat sensible cover 8 with the long hole 13 aproximately the same as or larger than the sectional form of the heat sensible instrument 7 is arranged to the upper heater 5, and the heat sensible instrument 7 is fitted. Consequently, a temperature rise of the heating box by the heater 5 is detected by the heat sensible instrument 7, and the heater 5 is ON-OFF controlled. The heat sensitivity of the heat sensible instrument 7 is not disturbed by the cover 8 and the instrument functions accurately because the sufficiently large long hole 13 is formed to the cover 8 for the heat sensible instrument at that time. Accordingly, the ammplitude of temperature of the central section of the heating box can be reduced. |
