| 摘要 |
<p>PURPOSE:To perform a precise analysis without a troublesome pretreatment by heating a sample for a certain time with high frequency power small not to burn the sample in the initial stage of the sample heating, and then burning the sample with large high frequency power. CONSTITUTION:The high frequency power supplied from an oscillating circuit 3 to the work coil 2 of a high frequency combustion furnace 1 is phase- controlled by a TRIAC 10. A DC signal of a fixed level or more as shown in the Figure 2 (B) is supplied as a trigger signal to the TRIAC 10, whereby the whole circuit is stabilized in the low current area of plate current of an oscillating tube 4, and a stable control can be performed even in small high frequency output area. Thus, output power as small as not burning or decarbonized the sample can be supplied to the furnace 1 in the initial stage of heating. The trigger signal is supplied to the TRIAC 10 through the photocoupler 23 of an insulating circuit by the ON of a transistor 27 by the control signal from a controller 29 connected to a CPU 30.</p> |
