To provide an outflow prevention device which is capable of preventing refrigerant from flowing out into a vehicle compartment even when an evaporator has ruptured. The device includes at least two litter boxes arranged as stacked drawers held in a housing. Then, the exposure adjustment that sets the determined aperture value, and the shutter speed and the gain corresponding to thereof as exposure control values. The program can access the cameras at different frame rates. The configuration of the output fiber allows for the removal of substantially the entire light from the inner cladding of the output fiber before the signal is emitted through the downstream end of the output fiber. The signal processor calculates a baseline corresponding to a representative amplitude of the similar amplitudes and provides a self-calibrated output signal.