METHOD FOR MEASURING CONCENTRATION OF ODORANT THT IN GAS

摘要

PURPOSE:To simply know the concn. of odorant tetrahydrothiophene (THT) with good accuracy on the basis of the preliminarily obtained relation of absorbancy and concn., by absorbing gas containing THT such as city gas with an I2-solution, and measuring ultraviolet absorbancy due to the formed complex. CONSTITUTION:0.01-0.02% I2-solution is put in a cell 4 and specimen gas is introduced into said cell 4 from a pump 7 through a filter 8. After a definite amount of the specimen gas has been passed through said I2-solution, the beam from a light source 1 is passed through a condensing lens 2 and an interference filter 3 to be incident to the cell 4. Transmitted light is passed through a condensing lens 5 and ultraviolet absorbancy is measured at 308nm by a detector 6. The concn. of THT in the specimen gas is accurately measured from concn. and absorbancy preliminarily obtained by using a known amount of THT within ten and several minutes per one specimen.