(1) direct weighing method: if the solid sample is not hygroscopic and is stable in the air, direct weighing method can be used. First in the balance that accurate quality of the clean container, and then use the spoon to take the right amount of sample is added to the container, said the total quality of it. The quality of the sample is obtained by reducing the value of the two mass.
(2) reduction method: in the analysis of the balance of the balance generally use the reduction method. First, weigh the exact quality of the sample and weighing bottle, then pour the sample in the weighing bottle to the container for the medicine to be put into the container, and the estimated quantity is close to the estimated quantity. The drug on the back cover of the weighing bottle, put in the balance and then accurately weighed its quality. Two times the difference is the quality of the sample quality. If a drug into the container must discard too much weight, do not put back the said flask. If the sample can not be added, it can be added again, but the number of times should be less.
(3) the method of designation: for a sample with relatively stable properties, sometimes a sample of specified quality can be called for the convenience of calculation. With the specified method when weighing in on both sides of the balance disc, put a dish (their quality as close as possible to the balance of the balance point), adjustment in the middle scale, then the left balance disc plus a fixed quantity of sample weights, the right balance disc plus (so to take samples more convenient), balance to balance the value, then the quality of the sample for the specified quality