| 摘要 |
PROBLEM TO BE SOLVED: To provide a flame atomic absorption spectrophotometer capable of executing always surely changeover from air-acetylene to dinitrogen monoxide-acetylene at an ignition time, when dinitrogen monoxide is used as supporting gas. SOLUTION: When producing a dinitrogen monoxide-acetylene flame, acetylene and air having a prescribed mixing ratio are supplied S31 to a burner and ignited S32. When the flame is stabilized, the quantity of light A0 from the flame is measured S33 and memorized in a memory, and an extending electromagnetic valve is opened at a prescribed primary opening to increase S34 the supply quantity of acetylene. The quantity of light A1 of the frame is measured S36 at this time, and the difference (A1-A0) between the quantity of light A1 and the memorized primary quantity of light A0 is calculated. If the difference of the quantity of light does not yet reach a reference value Ar, the supply quantity of acetylene gas is increased furthermore by retuning to S34. When the difference of the quantity of light reaches the reference value while the flow rate of the acetylene gas is increased, supporting gas is switched from the air to dinitrogen monoxide S38, S39.
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