Pressure bourdon tube type

We measured flow rate with a Varlan P/N 29-000086-00 Soap Bubble Meter. The pressure gauges were Heise bourdon-tube type with 0.1 psla divisions. The column was 16 feet of 1/4 inch copper tubing packed with Carbowax 20M loaded to 20% on Fluoropak 90. 

EXPLAIN how a bourdon tube-type pressure detector produces an output signal including ... 

The operation of bellows-type and bourdon tube-type pressure detectors is summarized below. 

The diaphragm-sealed, NaK-filled bourdon-tube type of pressure transmitter has been used with two different styles of diaphragms. A thin, 0.010- to 0.015-in.-thick metallic diaphragm is used to separate the Bi system... 

The indicator element measures the signal from the weighing element, and converts it into a readable form. It may be any of several different types, eg, the graduated beam of Figure 3, a Bourdon tube pressure gauge, or a numeric display device. Today (ca 1997), with the increase in automation, the indicator element may not display the weight but may instead transmit it electronically to a controller. 

Elastic-Element Methods Elastic-element pressure-measuring devices are those in which the measured pressure deforms some elastic material (usually metallic) within its elastic limit, the magnitude of the deformation being approximately proportional to the applied pressure. These devices may be loosely classified into three types Bourdon tube, bellows, and diaphragm. 

Mechanical Pressure Gauges The Bourdon-tube gauge indicates pressure by the amount of flection under internal pressure of an oval tube bent in an arc of a circle and closed at one end. These gauges are commercially available for all pressures below atmospheric and for pressures up to 700 MPa (about 100,000 Ibfliu") above atmospheric. Details on Bourdon-type gauges are given by Harland [Mach. Des., 40(22), 69-74 (Sept. 19, 1968)]. 

Conditions of Use Bourdon tubes shoula not be exposed to temperatures over about 65°C (about 150°F) unless the tubes are specifically designed for such operation. When the pressure of a hotter fluid is to be measured, some type of hquid seal should be used to keep the hot fluid from the tube. In using either a Bourdon or a diaphragm gauge to measure gas pressure, if the gauge is below the... 

The most frequently applied mechanical manometers in ventilation applications are fluid manometers, bur the following types are also used. The Bourdon tube is a small-voiume tube with an elliptic cross-section bent to the shape of a circular arc, the C-type. One end is open to the applied pressure while the other end is closed. The pressure inside the tube causes an elastic defonnation ot the tube and displaces the closed end, which is then converted, by means of a linkage mechanism, into the movement of a pointer. The Bourdon tube may be of a spiral or helical design as well. 

Other resistance-type transducers combine a bellows or a bourdon tube with a variable resistor, as shown in Figure 6. As pressure changes, the bellows will either expand or contract. This expansion and contraction causes the attached slider to move along the slidewire, increasing or decreasing the resistance, and thereby indicating an increase or decrease in pressure. 

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