BLACK LIGHT Main function: identify the world notes true and false, identify id, the bill is true or false. BLACK LIGHTDetector portable hand- ... true absorption of paper currency, no reflected light; counterfeit Qingbaikouan paper has a strong reflected light. 3, counterfeit money or logo watermark ... and negative on the 5th, in the case of light the dark, that is, replace the battery. BLACK LIGHT