I would think a decent load cell and readout would get within a lb or so. Does anybody know if there's one on the market. All I've ever seen is the Sherline. I made my own out of a cylinder and guage, but have verified it's accuracy with the scale at work, weighing a 700 lb forklift carriage on our calibrated shipping scale, and comparing my scale to it. The problem with the mechanical scales is they are a simple cylinder and are subject to friction losses of the sealing system. I usually take a measurement after pressing the tongue down on the scale several times until the needle settles on a number. Then I'll take a reading just setting it down on the scale without distrubing it. I then average the two numbers and it seems very accurate. YMMV.
