How To Use Glass Test Tubes Correctly?
1.Ordinary glass test tubes can be heated directly. Please wipe the water on the outer wall of the test tube before heating.It is better to use high borosilicate glass test tubes than ordinary glass test tubes to prevent heating crack.
2.When filling the solution, it shall not exceed 1/2 of the capacity of the test tube, and when heating, it shall not exceed 1/3 of the test tube.
3.When heating, use a test tube holder, which is inserted from the bottom of the test tube. When taking it out, take it out from the lower part of the test tube.The holding position is about 1/3 to the mouse of the test tube.
4.When heating, first heat the test tube evenly, then heat it centrally at the bottom of the test tube, and move the test tube constantly.
5.Do not quench after heating to prevent cracking.
6.When heating, the mouth of the test tube cannot face anyone. When heating the solid, the test tube should be placed horizontally with the mouth slightly inclined downward.
