I'm using this tool 100% for my archery needs.  I hook it up to a draw winch and use this item to measure the draw weight of my bows.  I've found it to be very accurate with my expectations of the bows used.  It's now become a very important tuning/measure device for me.  This saved me a lot of money compared to buying a labeled "draw weight scale" which can cost much much more, but essentially do the same thing!