For the sake of safety in working with the K-Ar isotope dilution method in our laboratory, a manifold system is used to prepare argon tracers without mercury cutoffs.In this laboratory, the ultra-high vaccum valve has been made of indium, as the latter possesses some favorable properties such as its adhesion on glass, lower melting point and lower vapor pressure. Besides, the pressure in ultra-high vacuum system is generally less than 10-8 torr.The method presented here will give reliable results to younger rock samples of over one million years in age.
. 1979, 测定地质年代的钾-氩稀释法. 地质科学, 14(2): 139-150.
. NOTE ON ISOTOPE DILUTION METHOD FOR K-Ar DATING[J]. Chinese Journal of Geology, 1979, 14(2): 139-150.