Abstract: A bar code scanning system and method for scanning a bar code containing a key including successively scanning the bar code and providing, for each scan, a plurality of data elements forming a scan fragment for at least a portion of the bar code, identifying each fragment containing a portion of a reference key, detecting when there has been a match between a reference key and the identified key fragments, determining if a complete key has been constructed from the key fragments, calculating a displacement between the key fragments which constructed the complete key, and aligning data fragments of the bar code by placing each successive data fragment in alignment with the previous data fragment offset by the amount of the displacement.

Abstract: A frequency division multiplexed bar code scanner system includes a plurality of radiation sources for simultaneously providing a plurality of source beams, and a modulator circuit for modulating the intensity of each source beam at a different frequency. The source beams are combined and directed along a path to a bar code to be read; the return combined reflected light patterns are amplitude modulated by the bar code and are detected and the amplitude modulation of at least one of these patterns is detected to obtain a representation of the bar code read. The phase shift between the source beam and at least one of the reflected light patterns is used to determine the distance to the barcode bearing object. Distance information may be used to improve barcode reading performance.

Abstract: A portable (handheld) volatile organic compound monitoring system for monitoring, for fugitive emissions, a device that includes a coded identification tag. The system includes a housing, a tag reader, analysis chamber structure, a sample probe coupled to the analysis chamber, and pump structure for drawing a gas sample to be analyzed through the sample probe into the analysis chamber. Ionization apparatus is coupled to the analysis chamber for ionizing a gas sample drawn into the analysis chamber from the device being monitored, and a sensor responsive to ionized gas in the chamber produces an output signal as a function of an ionization characteristic of the ionized gas. First storage stores a plurality of response factors as a function of various types of volatile organic compounds to be monitored, second storage stores tag information read by the tag reader, and circuitry responsive to tag information stored in the second storage selects a response factor from the first storage.