SPECTRACE

X-RAY FLUORESCENCE SPECTROMETER-NAMELY, SYSTEMS FOR DETECTING THE PRESENCE OF CHEMICAL ELEMENTS IN A SAMPLE, SAMPLE HOLDERS, RADIOACTIVE SOURCES, SOLID STATE DETECTORS WITH AND WITHOUT CRYOGENIC SUBSYSTEMS, MODULAR SIGNAL PROCESSING UNITS, MULTI-CHANNEL PULSE HEIGHT ANALYZERS, AND SUPPORTING SOFTWARE-NAMELY, MAGNETIC TAPE CASSETTES, AND COMPUTER-BASED PULSE HEIGHT ANALYSIS SUBSYSTEMS