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HGA-76型石墨炉是美国P-E460、603等原子吸收光谱仪的重要附件。使用中多数故障是由于三端双向可控硅的毛病引起。 HGA-76型石墨炉需要在极短的时间(两秒)内升温至2700℃,程序控制器中使用三端双向可控硅2N6162来控制炉体升温,可控硅所承受的电功率很大,发热相当严重,可控硅壳体的自然散热达不到这种速度的要求,而可控硅所能承受的最大电流直接受壳体温度的影响。壳体散热速度慢、效率差,温度就升高,能够承受的最大允许电流就迅速下降。
HGA-76-type graphite furnace is the United States P-E460, 603 and other atomic absorption spectrometer an important annex. Most of the faults in use are due to the triac failure. HGA-76-type graphite furnace needs to be heated to 2700 ℃ in a very short period of time (two seconds), the program controller uses triac 2N6162 to control the temperature of the furnace, and the SCR can withstand a large amount of electric power, Heat is quite serious, the natural heat of the thyristor shell can not reach the requirement of this speed, and the maximum current that SCR can bear is directly influenced by the temperature of the shell. Shell cooling slow, poor efficiency, the temperature rises, the maximum allowable current to withstand the rapid decline.