DiFluid Omni
The Agtron scale is to coffee roasting what the Pantone Matching System is to industries such as graphic design, fashion design, product design, printing, and manufacturing. Agtron offers an objective measure of colour which is correlated to the roast level of whole and ground coffee beans. It's a way for coffee roasters to take a quantitative approach to roasting quality control.
I've recently invested in a neat little device, the DiFluid Omni, which measures the colour of coffee beans as well as measuring the particle size and distribution of coffee grounds. I haven't yet spent much time measuring particle size but have been looking at the colour of my roasts. The Agtron scale specifies a number which relates to the roast colour. The lower the number the darker the roast, the higher the number the lighter the roast.
I am finding that I tend to roast on the lighter end of the medium roast spectrum (typically an Agtron of 60-65). This emphasises the fruity flavour characteristics of the coffee beans as well as balancing out the acidity of the extraction.
I expect to learn a lot from the Omni over the next little while!