1. select the PPR pipe as two long light, remnants of observation after burning. Remnants of the less the more pure, more containing more impurities.
2."one yuan coin after 2004, the standard weight is 6 grams." One dollar coin was put aside, and then the PPR tube was cut off and weighed on the electronic scale. Finally, the PPR tube used for the experiment was 60 grams, that is 10 times the weight of the coin. Then, in the PPR tube cut a small mouth, a coin card will go. Then he prepares a basin of water.
An important step to the card with a coin PPR tube placed in the water, floating on the surface of PPR tube.
"This PPR tube is real." If the PPR tube into the water, then the PPR tube must not impurities such as calcium carbonate.