TWOOWAVELENGTH SPECTROPHOTOMETER FOR CHECKING CONTENT IN CONTAINER* ESPECIALLY FOR DETECTING LEAKAGE THROUGH CONTAINER

摘要

A dual wavelength spectrophotometer for ampoule content inspection, in particular for a ampoule leak detection using the so- called dye bath immersion technique. Light transmitted through the ampoule 3 is received by a bifurcated fiber optic cable 4 providing via a random mix arrangement substantially identical ampoule optical signature signals. Each is directed through preselected interference filters 5, 6, chosen on the one hand on the basis of the dye being used and the glass ampoule and its contents on the other hand. Associated with the filters are respective photodetectors 9, 10, the output signals of which are connected to a difference amplifier 11. The output of the latter is compared in comparator 13 with a preestablished threshold signal, which represents the minimum level of dye from which to effect a reject status. The ampoule contents or a particular component thereof may also be investigated in this manner. The photodetector outputs are also summed in summing amplifier 12 and the resultant compared in another comparator with a second preestablished threshold in order to provide a fail-safe system capability against optical failure and the like. The difference signal/comparison circuit leg may be constructed to provide logarithmic function capability and thus produce an output which is proportional to concentration. Therefrom the concentration of the ampoule contents or the dye can be determined, for example to lie within a preestablished "window". IMAGE