PURPOSE: To obtain an accurate emissivity measuring instruments by connecting the cooling layer of an airtight structure airtightly with the opening part of a blackbody furnace having airtight structure.
CONSTITUTION: A front cover 25 is closed and the insides of the furnace body 11 and the cooling layer 20 are maintained airtightly and at the same time, a bar- shaped member 28 setting a sample 2 at an end is operated to locate the sample 2 at the bottom side A of the furnace. Then, after the insides of the furnace body 11 and the cooling layer 20 are evacuated of purged with a specified gas atmosphere via a pierced hole 23, a heater 5 is controlled to heat the furnace body 11 and heat the sample 2 to the prescribed temperature. On the other hand, the cooling layer 20 is usually water-cooled but water-cooling is unnecessary when the measuring temperature is high and the emissivity of the sample 2 is high. Further, when the temperature is low and water-cooling is not available, the temperature of the cooling layer 20 is measured and an amount contributed by the background radiation is corrected. Thus, the accurate radioactivitiy is measured.
YAMADA TAKEO
HARADA NAOKI
IMAI KIYOTAKA
HISHIKARI ISAO
SHIMIZU TAKAO
CHINO WORKS LTD