Bourdon vacuum gauges

Bourdon vacuum gauge Diaphragm vacuum gauge... 

Higher pressures are commonly measured with Bourdon tube gauges as seen in Figure 33.15. Bourdon tube gauges can be designed to measure vacuum pressures or positive pressures. Bourdon tube gauges display the pressure by the displacement of a... 

Gases are transferred in a standard Pyrex glass vacuum line equipped with high-vacuum stopcocks (lubricated with a fluorocarbon grease [Halocarbon]) to which is attached a four-trap system used for low-temperature trap-to-trap distillation (Fig. 1). Because of the reactivity of the compounds, a Heise-Bourdon tube gauge [Dresser Ind.], is used for PVT measurements. 

Fig. I. Standard Pyrex glass vacuum line a, thermocouple gauge [Fredericks] b, Heise-Bourdon tube gauge [Dresser] c, reservoir, 500 mL d, removable cold trap e, removable U-trap /, 18/9 ball-and-socket joint g, 2-mm Pyrex high-vacuum stopcock [Kontes] h, three-way high-vacuum stopcock i, Pyrex glass manifold, 10-12-mm diam j, Pyrex glass traps to fit into a standard Dewar flask k, 10/30 outer joint.

A metal (stainless steel, nickel or Monel) vacuum line is constructed in a well-ventilated hood/ This line is equipped with a Bourdon tube gauge [Dresser Industries] with a range of at least 0-1500 torr. A small cylinder (0.5 lb) of fluorine [Matheson] is stored behind a suitable barricade [Matheson]. The cylinder is equipped with a standard two-stage regulator [Matheson] and then connected to the metal line via /4-in. copper, nickel, or Monel tubing. 

Freshly distilled sulfur dichloride (0.612 g, 6 mmol) and trimethylsilyl cyanide [Aldrich] (1.19 g, 12 mmol) are condensed at - 196° into a 50-mL Pyrex round-bottomed flask that is equipped with a Kontes Teflon stopcock to which is attached a 10/30 inner standard taper joint. A Teflon-coated stirring bar is placed in the vessel. The reaction vessel is connected to the vacuum line by a 10/30 outer Joint. The vacuum system is equipped with a Heise Bourdon tube gauge [Dresser Industries] and a Televac thermocouple gauge [Fredericks]. The quantities of SCI2 and (CH3)3SiCN are measured in the vacuum line by means of PVT techniques, assuming ideal gas behavior. 

Figure 7.1 Cut-away view of a Bourdon tube-vacuum gauge (measurement against ambient atmospheric pressure).

Bourdon and diaphragm gauges that show both pressure and vacuum indications on the same dial are called compound gauges. 

Bourdon gauges are used to measure fluid pressures from nearly perfect vacuums to about 7000 atm. More accurate measurements of pressures below about 3 atm are provided by manometers. 

Valve, 10) Balance, 11) Mercury storage vessel, 12) PVC-tubes, 13) Bourdon-gauge, 14) Vacuum meter, 15) Valve, 16) Needle valve, 17) Safety valve. 

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