METHOD FOR MEASURING SMALL AMOUNT OF IMPURITIES WITHIN GAS

摘要

PURPOSE:To enable a concentration of a small amount of impurities contained within a chemical substance to be measured by introducing a chemical substance in gas shape at normal temperatures and normal pressures into a cell in a state of liquefied gas and then measuring a conductivity of the liquefied gas. CONSTITUTION:A liquefied gas to be measured is introduced into a pressure- resistance container 1 which is also used as an external pole through a joint 4 by an introduction port 2. A conductivity of the liquefied gas to be measured is measured by this container 1 and an inner electrode 11 which is provided concentrically in reference to the container 1 and an impurity concentration within the liquefied gas is measured according to a relationship between the impurity concentration and the conductivity within the chemical substance which is obtained previously. The liquefied gas after measurement is connected to an external semiconductor manufacturing device by an out port 5 through a joint 5.