1, when adjusting the balance nut, when adding or subtracting weights, when exchanging weights, when dialing the traveling code, stop with the stopper after use; After use, the hook of the scale should also be removed from the blade, that is to say, the blade should not be disturbed as much as possible, which is to protect the blade. Before use, adjust the level with a spirit level, carefully zero with a balance nut, pick up and put the weight with tweezers and move the yard, and then observe the balance with a pendulum needle and a ruler. These are all to ensure the measurement accuracy.

2. When measuring the density of solids by hydrostatic weighing method or pycnometer method, bubbles (obviously) attached to the surface of solids must be stirred away, otherwise experimental errors (not "errors") will be caused, and the measured apparent weight of solids (or the total mass of pycnometer) will be less than the actual value. In this way, the experimental result is actually the average density of the block and bubble, which is obviously smaller than the density of the block itself.

3. The best way is to copy the name method (one of the York methods). That is, the left object and the right code are weighed once, and the reading m1is obtained; Weigh the left code and the right object again and get a reading M2. Using the lever principle, it is easy to prove that the result is M = root sign (M 1 times M2), that is, the geometric average of the two. This method not only eliminates the unequal arm error of the balance, but also bypasses the measurement of the actual arm length of the balance, which is convenient and accurate.