Sensors helical tube

Other types of these gauges include the twist tube, spiral tube, and helical tube. Diaphragm and bellows gauges are two other types of pressure sensor that were developed later. For more details on Bourdon tube materials and design, refer to Giacobbe and Bounds [1], Goitein [2], and Considine [3]. 

Cultivation of the cyanobacterium was performed in a 4.35 L automated helical photobioreactor (PhBR) described by Tsygankov et al. (1998a). A. variabilis PK 84 was cultivated autotrophically in the PhBR under sterile air containing 2% C02 (500 ml-min 1). Growth conditions in the PhBR were monitored by a computer system connected to built-in pH, temperature, optical density, pO, and sunlight intensity sensors. When necessary 1 or 2 polyurethane foam balls were circulated along with the culture in the PhBR to clean the inner surface of the PVC tubing. 

Conducting-polymer actuators have been developed for several applications by the Wollongong group [9]. These include the use of bUayer PPy actuators in a cochlear ear implant [85]. Hollow-tube actuators with helical wire interconnects have also been developed for use in an electronic Braille screen [39]. A trilayer actuator valve has been included in a combined sensor-actuator system to control a gas valve inlet for food... 

We have reported examples for the formation of tubular structures with the help of block copolymers, in most cases with amphiphilic blocks or alternating copolymers. They have all been engineered in such a way that they self-assemble into vesicles, fibers, or tubes. The mechanism for the formation of those tubes, with hollow insides in some cases, was described through two possible routes, which shows how powerful block copolymers can be. Furthermore, the field of applications is very broad material sciences, catalysis, smaller electronic devices, strong nanocomposites, sensors, ion transport, and many others. Creating helical structures or tubes is also interesting in order to mimic nature and to try to understand the way they are created in biological systems. 

Pressure-sensing elements (a) flat diaphragm (b) corrugated diaphragm (c) capsule (d) bellows (e) straight tube (f) Cshaped Bourdon tube (g) twisted Bourdon tube (h) helical Bourdon tube (i) spiral Bourdon tube. (From Norton, H.N., Handbook of Transducers, Englewood Cliffe, NI Prentice-Hall, 1989, 294-330. Reprinted with permission.) Previously published in Chau, K.H.L., Pressure and sound measurement, in The Measurement, Instrumentation, and Sensors Handbook, Webster, I.G., Ed., CRC Press, Boca Raton, FL, 1999, p. 26-3.)... 

Classical pressure sensors are the purely mechanical pressure gauges (Table 14.2). Reasons for their wide use are robustness, low price, simple installation, and independence from electric power supplies. In the so-called Bourdon gauge, a dead-end tube in helical form with several turns expands due to elastic deformation when pressure is increased. This movement is transferred mechanically to a mostly circular scale. Although these instruments can be overloaded, it is common practice to operate them at no more than three-quarters of their full scale. These gauges are manufactured by a large number of companies and can be obtained in various qualities Table 14.3 gives advice on what to consider while choosing. 

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