Vacuum gauge (Vacuum Gauge) relevant knowledge
From;    Author:Stand originally
Use at measuring the meter of the rare gas total pressure under atmosphere, weigh vacuum compasses again. The measurement of vacuum gauge pressure of unit continue to use measures an unit, the international unit of pressure is handkerchief (Pa) , the unit that ever used still has hold in the palm (Torr) and millibar (Mbar) .

Brief history from 1643 Italian physicist E. Hold in the palm in since tearing open benefit to have atmosphere force test, appear early or late make a variety of vacuum gauge. What appear the earliest is vacuum gauge of U form canal, it can be used only measure thick vacuum and low vacuum. 1874, h.G. Wheat overcomes what fatigue invents to compress type vacuum gauge, solved the measurement of the absolutely pressure of low vacuum and high vacuum, but still cannot undertake be metricaled continuously. 1906, m. Leather La Buddhist nun invents resistor type vacuum gauge, the low vacuum in solving industry to produce measures an issue. Then, o.E. Barkley invented ionization vacuum gauge again 1916, this is measured in the high vacuum that solved handkerchief of 10-1 ~ 10-5 not only at that time, and promoted oil to diffuse the development of the vacuum equipment such as pump and application. 1937, f.M. Pan Ning invents vacuum gauge of cold cathode ionization, apply to have a large number of deflate and often expose the measurement at atmospheric vacuum equipment, get applied extensively in vacuum metallurgy and machinist job so. 1950, r.T. Bayard and D.A. Aerbaite invents vacuum gauge of BA type ionization, the ultrahigh vacuum that solved 10-8 handkerchief measures an issue, make vacuum is measured thereby achieved a breakthrough, promoted the development of ultrahigh vacuum technology; And the science and technology such as the exterior physics that concerns with this, nuclear energy, spaceflight and large integrated circuit also got developing quickly. Since 1960, the modulation plan that develops a success in succession, ultrahigh vacuum that restrains compasses, turn to note compasses, separate plan and magnetism to accuse type ionization compasses to wait to already can realize 10-11 handkerchief to control is measured.

Classified vacuum gauge can be divided for absolutely vacuum gauge and opposite vacuum gauge two kinds big. The physical quantity that every can measure from its itself (fluid of height of the column that be like fluid, job, proportion) calculate those who give aeriform pressure to weigh absolutely vacuum gauge directly, this kind of vacuum gauge measures precision taller, basically use as standard measure. The certain physics that basically uses gas to fall in low-pressure force relative to vacuum gauge is characteristic (if heat is conducted, ionization, viscosity and meet an emergency) the relation indirect measurement with pressure, its measure precision inferior, and measure a result to still be concerned with sort of the gas that be measured and composition. Because this is opposite,vacuum gauge must be mixed with demarcate of absolutely vacuum gauge calibration is rear can use as vacuum is measured. But it can numerate directly the pressure that be measured, use convenient, great majority is held in applying actually. The pressure range that vacuum technique needs to measure is handkerchief of 105 ~ 10-11, smaller even, wide amount to above of 16 amounts class, still can apply to without a kind of vacuum gauge from thick vacuum (102 handkerchief of 105 ~ ) , low vacuum (handkerchief of 102 ~ 10-1) , high vacuum (handkerchief of 10-1 ~ 10-5) , ultrahigh vacuum (be less than 10-5 handkerchief) to extremely high vacuum (be less than 10-10 handkerchief) full range is measured, have a variety of vacuum gauge consequently. The most commonly used U form provides vacuum gauge, compress vacuum gauge of ionization of type vacuum gauge, resistor vacuum gauge and cold heat cathode.
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