An integrated wavelength selectable photodiode includes a device package having an input that receives an optical signal. An embodiment of a portable device comprises a memory device and a processing unit. The invention is adopted to solve problems arising from the pressure increasing and the quartz cassettes breaking easily due to moisture in a low temperature portion of the high temperature gas discharged from a high temperature oven entering the cooling processing device, thereby improving manufacturing efficiency and reducing the manufacturing cost. A radiometer may be inserted into fluid treatment chamber to calibrate the light sensing system.