Gauges, vacuum

Large storage tanks are designed to withstand low pressures and vacuums. Typically they are constructed to withstand no more than 8 in of water gauge pressure and 2.5 in of water gauge vacuum. A particular tank is 30 ft in diameter. 

Storage tanks typically are not capable of withstanding much pressure or vacuum. Standard storage tanks are designed for a maximum of 2.5 in of water gauge vacuum (0.1 psi) and about 6 in of water gauge pressure (0.2 psi). 

M. W. Evans, P. K. Anastasovski, T. E. Bearden, et al., Energy inherent in the pure gauge vacuum, Physica Scripta (in press). 

The simplest example of the generation of energy from a pure gauge vacuum is to consider the case of an electromagnetic potential plane wave defined by... 

In a U(l) invariant theory, the pure gauge vacuum is defined by a scalar internal gauge space in which there exist the independent complex scalar fields ... 

It can be shown as follows that the transition from a pure vacuum to a pure gauge vacuum is described by the spacetime translation generator of the Poincare group. The pure vacuum on the U(l) invariant level is described by the held equations ... 

Essentially, this replacement means that the spacetime changes from one that is conformally flat to one that is conformally curved in other words, the axes vary from point to point whenever a covariant derivative is used for any gauge group symmetry. It is this variation of the axes that introduces energy into a pure gauge vacuum. The covariant derivative in the latter is... 

The action is therefore not invariant under local gauge transformation. To restore invariance the four potential, A must be introduced into the pure gauge vacuum to give the Lagrangian... 

The total Lagrangian if I X I if2 is now invariant under the local gauge transformation because of the introduction of the 4-potential A, which couples to the current of the complex A of the pure gauge vacuum. The field A also contributes to the Lagrangian, and since if + ifj + if2 is invariant, an extra term if3 appears, which must also be gauge-invariant. This can be so only if the electromagnetic field is introduced... 

Vessels used for the degassing of prepolymers must be designed to withstand the 250 to 280 Pa gauge vacuum applied. The exhaust fumes from the... 

FT-NMR spectrometer, with 10- or 15-mm-diameter probe capability if possible gas NMR tube with concentric Teflon valve (e.g., J. Young NMR-10) 1-L reaction flask with greaseless stopcock 0- to 1-bar pressure gauge vacuum line Ultra-Torr fittings microsyringes hot plate and oil bath with 0 to 200°C thermometer liquid N2 and ice baths benzoyl chloride and bromide, D2O (95 percent) fume hood. 

GAUGE VACUUM - Instrument used to measure pressures below atmospheric pressure. 

The integration of vacuum system and gas distribution is mainly for pumping vacuum in pipeline, vacuum chamber and gas distribution tank. It consists of vacuum pressure gauge, vacuum pump, electromagnetic valve and jointing pipeline. 

Figure 4.21 Diagram of the VIP mounting the spinning rotor gauge. Vacuum tightness is ensured by a high vacuum epoxy resin.

Instruments provided temperature gauge, vacuum gauge, relative humidity gauge etc. 

Liberman L, Dershaw DD, Morris EA, Abramson AF, Thornton CM, Rosen PP (1997a) Clip placement after stereotactic vacuum-assisted breast biopsy. Radiology 205 417-422 Liberman L, Hann LE, Dershaw DD, Morris EA, Abramson AF, Rosen PP (1997b) Mammographic findings after stereo-tacic 14-gauge vacuum biopsy. Radiology 203 343-347... 

Philpotts LE, Shaheen NA, Carter D, Lange RC, Lee CH (1999) Comparison of rebiopsy rates after stereotactic core needle biopsy of the breast with 11-gauge vacuum suction probe versus 14-gauge needle and automatic gun. AJR Am J Roentgenol 172 683-687... 

Answer by Author Yes, we have subjected some of them to perhaps a dozen cycles between room temperature, liquid nitrogen, and liquid hydrogen. This has been to a thermocouple gauge vacuum only. 

Bayard-Alpert gauge (vacuum technology) A hot cathode ionization gauge using a fine-wire ion collector to minimize X-ray effects in the gauge. 

Cold cathode ionization gauge (vacuum technology) An ionization-type vacuum gauge where the electrons for ionization are usually produced by a secondary electron-emitting surface or a radioactive material. Often uses a magnetic field to increase the path length of the electrons. 

Drift, gauge (vacuum technology) The change of calibration of a sensor with time or use. 

Ionization gauge (vacuum technology) A vacuum gauge that uses the ion current formed by electron-atom collisions as an indicator of the gas pressure (density). The electrons are formed as secondary electrons from ion bombardment or from a hot thermoelectron-emitting filament. See also Vacuum gauge. 

Nude gauge (vacuum technology) A vacuum gauge that is inserted directly into the chamber volume and has no envelope or tabulation. 

Penning vacuum gauge (vacuum technology) An ionization vacuum gauge in which the electric and magnetic fields are approximately parallel. Also called the Phillips ionization gauge. See also Vacuum gauge. 

Row meter temperature gauge Vacuum gauge. See also Feedback. 

Thermistor gauge (vacuum technology) A form of the Pirani gauge (see Vacuum gauge, Pirani) in which the resistor element is a semiconductor material rather than a metal. 

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