| 摘要 |
PURPOSE:To enable an accurate measurement to be performed without being affected by an ambient gas by measuring the illuminance of ultraviolet rays while making a gas flow in a pipe provided with a glass for transmitting ultraviolet rays at one end and an ultraviolet ray detector at the outer end. CONSTITUTION:A gas inlet 14 and a gas outlet 15 are formed in a pipe 13 provided with an ultraviolet ray transmitting glass (quartz or the like) 11 at one end and an ultraviolet ray detector 12 at the other end. The ultraviolet ray transmitting glass 11 is made close to an ultraviolet ray source (lamp) 16 and a measurement is conducted while such a gas as nitrogen gas is made to flow in the pipe 13. Thus, since a substance, such as ozone, that absorbs a wavelength 254nm is not produced in the pipe 13, ultraviolet rays can be accurately measured regardless of the condition of an ambient gas. |
