The multichannel analyser (MSA) has been the workhorse of spectroscopic measurements since the 1940s. The MCA has evolved from a very simple device capably of the basic sorting (histogram) of the information into a complete signal processing platform. This presentation begins with a brief history of the MCA and then highlights what makes DSP based solutions better than the analogue based solutions of the past. Since the ADC is a key element of the DSP based instrument the advancements in high speed ADCs will be reviewed in regard to how their speed, number of bits and other performance factors impact the quality of the spectroscopic data. The additional benefits that digital processing brings to the user such as enhanced diagnostic capabilities will also be highlighted. A discussion of advanced data acquisition techniques will be provided to demonstrate the power and versatility of digital instruments such as the Canberra Lynx? Digital Signal Analyzer. Some real world examples are provided to highlight why DSP based instruments can provide the best resolution, count rate performance, spectrum stability and wider dynamic range than previous systems. Results from the Lynx under variable measurement conditions will be provided to enforce these concepts. The value of Loss Free Counting or measurement of short lived sampled or transient events will be reviewed. The value of Time Stamped List mode will be discussed and why this older technique is now being utilized once again within the scientific community. A review of benefits that Multi-Spectrum Scaling mode can bring to a wide variety of measurement applications requiring continuity of measurements will be provided.
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