Outgassing of VACUFER samples with different heating procedures

Abstract VACUFER was intended to be used in high pressure mercury vapour lamps instead of NiMn alloys for economic reasons. As gases released from hot parts may influence the performance of the luminescence layers, outgassing measurements are of basic importance. The samples were chemically cleaned before the measurements and outgassing was done by two heating procedures in two different vacuum systems. In one system the samples were heated from ambient temperature to 1250 K at 10 K min −1 . In the other system they were transferred onto a preheated filament at 1400 K. Out of the various VACUFER charges studied at Tungsram, two were measured at Seibersdorf. For these, the data spread of the measured total gas amounts released per gram of material was within the range of 40 and 60%. The samples showed significant differences with respect to the ratios of CO 2 /CO and H 2 O/H 2 .