Posted 01/09/2013 5:14 pm
This is an easy physical test to do and only requires measuring the weight and volume of the item in question. Measuring the volume of a coin is a simple matter of knowing the diameter and the thickness and then calculating the volume via the old: V = pi x (1/2 x D)^2 x H, where pi = 3.142, D = diameter in cm, and H = thickness in cm. The result will be in cubic centimeters or CCs. Weigh the coin to get the grams it weighs and then divide the weight by the volume. For pure silver, this will be 10.49. It will be less for sterling silver, since it is only 92.5% silver, and for coins of lower than .999 silver content.
Measuring the volume of an irregularly shaped object, like a fork or a pepper shaker is more difficult, so people tend to use water displacement to measure it. This is usually done by taking a 250 ml graduated cylinder, filling it with water to exactly 150-200 mls, and then placing the item in question in the cylinder to see how high the water level rises due to the object being inserted into the cylinder. The difference in CCs or mls is the volume of the item.
I've never seen a machine that can do this. It is simple enough and only requires the two parts, the graduated cylinder and a small electronic scale, to do the test. Only problem is when the item to be tested is too big to fit inside the graduated cylinder, which tends to be narrow and tall. There are plastic graduated cylinders that are shorter and fatter. While this works better with bigger items, the volume readings may not be quite as accurate for smaller items.
Measuring the volume of an irregularly shaped object, like a fork or a pepper shaker is more difficult, so people tend to use water displacement to measure it. This is usually done by taking a 250 ml graduated cylinder, filling it with water to exactly 150-200 mls, and then placing the item in question in the cylinder to see how high the water level rises due to the object being inserted into the cylinder. The difference in CCs or mls is the volume of the item.
I've never seen a machine that can do this. It is simple enough and only requires the two parts, the graduated cylinder and a small electronic scale, to do the test. Only problem is when the item to be tested is too big to fit inside the graduated cylinder, which tends to be narrow and tall. There are plastic graduated cylinders that are shorter and fatter. While this works better with bigger items, the volume readings may not be quite as accurate for smaller items.
