How do you get the mass of substance using platform balance?

Answer 1

Place the unknown on one pan. If the unknown requires a tray, get two identical trays and put one on each pan, and the unknown in the other tray. If necessary, check initial zero balance by putting nothing but the trays on the balance. Estimate the initial mass, and place a standard mass on the other tray. Go up and down in the set of standards. Once you overbalance the unknown, go down only, adding and removing one standard at a time until the balance is reached. The standards are made in a binary set, such as 1, 2, 4, 8, 16, 32, grams, etc. If you put a standard on and it overbalances, take it off, if it underbalances, leave it on. Then go to the next smaller standard. (This assumes that you started by finding a standard that overbalances the unknown.) As you get closer and closer you may need to close the doors and wait for things to settle out. Some balances have little weights on the beam that you can move to get very fine resolution. When you have reached the desired resolution, add up the weights of all the standards you used. That is the mass of the unknown, plus or minus any error in the balance and one half of the smallest standard used. NEVER touch any part of the balance internals or the standards with your hands. Use the supplied tools.