A weighing scale should have a capacity of 10 to 30 pounds or more, and should be graduated to 1 ounce or less. Among good types on the market are the hanging-pan spring scale, the counter beam scale, and the beam scale of the steelyard type designed to hang from a bracket. The cheap scale in which the commodity pan stands above the spring, is likely to be inaccurate.

To use the scale properly, the following precautions should be observed: (1) Handle it carefully, and keep it clean and dry.

(2) Keep it in balance. A properly constructed scale will rarely get out of balance, but the proper way of adjusting a particular kind of scale should be learned. (3) Keep the eye squarely in front of the point of the scale that is being read. (4) Do not weigh a commodity in cardboard or other heavy covering without weighing the covering separately and deducting its weight from the total weight.

* The following material in this chapter, with the exception of the tables indicated, is condensed from Measurements for the Household, Circ. 55, published by the Bur. of Standards, U. S. Dept. of Commerce.