| 摘要 |
PURPOSE:To enable measurement of trace content of Mg quickly at a high accuracy by a method wherein a pulse discharge is performed with a sample containing Mg as electrode and a representative value of the intensity of a photocurrent is calculated for a time zone to be compared with a measured value data as known content when the photocurrent becomes constant after the start of the discharge. CONSTITUTION:When measuring a trace of Mg in steel or the like, a pulse discharge is performed with a light emitter 7 with a sample as electrode and an emitted light is converted into a photocurrent with photoelectron multipliers 2 and 2' after subjected to a spectroscope with a diffraction grating 1. Then, a photocurrent stored in photocurrent intensity memory circuits 3 and 3' is taken sequentially according to a discharge circuit controller 8, distributed with a memory position selecting circuit 4 and memorized in memories 5 and 5'. For example, 2,000-6,000 pulses after the start of the discharge are set aside as predischarge zone and arbitrary intensity of the photocurrent equivalent to 20-50% of a cumulative frequency distribution thereof is calculated as representative value with an arithmetic unit 6 in the measuring time zone between 2,000 and 8,000 pulses following thereof. The value thus obtained is compared with a representitative value which is predetermined from a standard sample containing a known Mg and stored in a memory device 9 by means of a comparator circuit 10 and the results are indicated on a display 11. |
