Update of the EPSON method for PFC measurement using FT-IR

In this paper, I describe the update of the EPSON Method for PFC measurement using FT-IR. The previous version of the EPSON Method can not cover the measurement for higher concentration exhaust, due to the IR absorption saturation. The IR absorption depends on the pressure. The reduction of pressure can make high concentration measurement easier. This technique is useful for the gases which are easy to saturate for its absorbance. The EPSON Method has been updated, and provides wide concentration range measurement without increased difficulty in the test procedure or expense.