Manometers with quartz spiral

G. Bourdon Gauges. As an alternative to mercury manometers there is a variety of gauges based on mechanical or electrical pressure transducers. This section presents a description of purely mechanical gauges which still find use in this electronic age.4 The metal Bourdon gauge (Fig. 7.5) is fashioned around a semicircular thin-walled metal tube with mechanical linkage to a pointer. Fused-quartz spiral gauges are also available. In this case, a thin spiral is sensitive to a pressure differential, and the deflection is balanced with air pressure in the surrounding envelope. The air pressure is then measured with a manometer. 

For work with low-boiling fluorides it is useful to have on hand a part-glass, part-quartz vacuum system provided with a spiral quartz manometer. 

Premier and Schupp have made vapour-density measurements with sulphur enclosed in a quartz bulb heated electrically and connected with a manometer consisting of a spiral of silica tubing attached to a small mirror. The pressure was measured by the amount of unwinding of the spiral. The same method has been used by Bodenstein and Katavama in studving the equilibrium ... 

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