What hardware handles the quality
first of all, we can distinguish from noise ( With a hard knock gently shake handshandle tube) Noise, the shake handshandle of enough thick tube should be more clear, and thin tube is boring. First can tell from the handle, the shake handshandle of thin tube heat transfer is fast, soon full new temperature, and the shake handshandle of enough thickness over a period of time is still very cold.
then there is the permission ( The most simple) , sawing handle tube inside it, the results are obtained. Except for macroscopic and mesoscopic scale measurement is relatively good method should be the handle on the whole piece of glass, like a touch of signs of both shake shake handshandle, this handle is not enough, still need to improve, touch is good shake handshandle should be immobilized, founder of directly.