Spectral characteristics of high-frequency discharges in hollow-electrode lamps

Determination of metallurgically dissolved nitrogen in aluminum-killed, low-carbon steel by hot extraction with hydrogen

“…Any increase over this rate had no practical effect. Optimum temperature was established in the range of 500-600 °C-near the base of the precipitation curve for aluminum nitride in steel (2). It was, therefore, decided to hold the flow rate of the hydrogen at 130 ml/min and the temperature in the range of 550-600 °C.…”

“…Earlier studies of the precipitation of aluminum nitride in steel, published by Beeghly (2), suggested that the temperature of the extraction procedure would be critical. Because 750-950 °C represented the range of optimum nitride precipitation, it was clear that this temperature region was unsuitable.…”

Emission spectrometry

“…Atkinson, Chapman, and Krause (17) investigated the spectra of potassium and rubidium emitted from such lamps, with particular attention to the effect of the operating parameters on the intensities, half-widths, and selfreversals of the lines. The use of electrodeless lamps in atomic absorption analysis was studied by Ivanov et al Bodretsova, L'vov, and Mosichev (51) powered a hollow-cathode lamp from a high-frequency supply and found an intensity gain of about two orders of magnitude as compared to lamps excited with dc power, with no increase in selfabsorption. The effect of a microwave field on emission of sodium in a hydrogen-oxygen flame was reported by Rosenthal and Eyer (518), who also found an intensity increase by two orders of magnitude even though the microwave power, at 2.5 GHz, was estimated to be only about 4/s the thermal energy of the flame.…”