Infrared absorbing compounds are disclosed. The liquid absorbing member permits part of a liquid from the circulation unit to flow therethrough toward the liquid leak sensor. by degradation of reliability of the detection results of reference parameters other than controlled variables, thereby making it possible to ensure a high accuracy of control. Values for options for the compiling of the graphical model to program code and to the executable control program can be preset thereby granularly with the automatic avoidance of conflicting presettings of values for these options.