สุญญากาศคืออะไร? |
Written by Administrator |
Tuesday, 10 October 2006 23:15 |
สุญญากาศ (vacuum) หมายถึง ที่ว่างซึ่งไม่มีแก๊สอยู่ แต่ในเชิงวิชาการหมายถึงภายในภาชนะที่มีความดันต่ำกว่าบรรยากาศ It is only since the 17th century that people became aware of the existence of vacuum. People like Galileo, Torricelli and von Guericke were the first to build equipment using vacuum as the principle of operation. One of the first main applications of vacuum was the development of electric lighting in the 19th century. In industrial vacuum processes, 4 pressure regions can be distinguished:
Recalculation between the several units for pressure is straight forward, since they are all lineary proportional. Their value for ambient atmospheric pressure is given below, allowing conversion between the different pressure units:
At present, the fields of application of vacuum techniques are multiple:
Future tendencies in the vacuum market are difficult to predict, though some trends can be expected:
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Last Updated ( Friday, 05 February 2016 08:14 ) |