You get a piece of graph paper and set up a graph. Draw weight on the side, one square per pound. Draw length on the base. One square per inch. Start the draw length at your brace height.

Then, using scales and some way to measure, like an arrow marked in inches, start at brace height and check the draw weight at each inch of draw. It is VERY important (and practically impossible to do by hand) to maintain the pull cycle all the way through the letoff and through the valley.

When you get the points plotted and draw out the line on the graph, then you count the squares under the line and that gives you your stored energy, each square is one pound.

While you' ve got the bow on the scales, you can measure the whole thing through the letdown cycle and plot that line as well. That tells you how much friction you have in the system (static hysterisis) which is also an indicator of how efficient your bow is.

If you' ll look at Norb Mullaney' s bow reports in Bowhunting World Magazine, then you can see how to set up the graphs. I' ve got most of his terminology figured out, but I' m still stumped on what the dickens ' virtual mass' is.