Temperature difference measures an effect to compasses canal
From;    Author:Stand originally
Vacuum room has Leng Bi, cold trap or heat source sometimes, such meetings make compasses canal is in room temperature, and temperature of vacuum room space is in microtherm or high temperature falls; Perhaps be in when vacuum compasses canal corrective as different as the temperature when measuring, two kinds of circumstances issue above, can cause an error. And the discretion of this kind of influence and pressure is concerned. (1) pressure is higher (P >130 Pa, firm ground is told below λ<<d) circumstance, become when pressure is higher, want two to be linked together only container is in balance position, criterion no matter its are both temperature is equal, its pressure should be equal. If pursue 5, according to P=nkT of aeriform pressure formula, have NLKTL=n2KT2, be like T1≠Tz, NL≠n2, have Fall in high-pressured strength condition namely, be in the vacuum system memory below balance position to be when temperature is inhomogenous, its element density and absolutely temperature become inverse ratio. Above circumstance the vacuum appearance to measuring pressure directly (like U model plan, compress vacuum gauge of type vacuum gauge, filmy type) did not affect, but the vacuum appearance that spends to measure vacuum according to the size of aeriform element density (like vacuum gauge of high-pressured force ionization) can produce an error. If the temperature when if these vacuum appearance are mixed in calibration,be being measured is different, its are measured result general is amended with next type The P in type1—— temperature isT1The calibration pressure when is worth P2—— temperature is T2calibration pressure value because T1With T2It is absolutely temperature, be like T1With T2All be in normal temperature condition, although T1≠T2, it is not quite big that its are affected when making nicety measure only, just need to use formula (2) undertakes correction. Graph the sketch map that 5 temperature affect to measuring (2) low-pressure force (lie when container below λ>>d) circumstance below low-pressure strength condition, the others circumstance still is like a graph 5 identical, existing to heat up transpiration phenomenon at this moment. Because at this moment the athletic condition of aeriform member state is in molecular state, two when be in balance position to fall are linked together container, in element of the gas inside unit time from container 1 enter container the molecular number of 2 and from container 2 enter container the molecular number of 1 is respectively The T in type1, T2—— is the temperature T of canal of compasses of the vacuum when calibration and calibration system respectively
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