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Unformatted text preview: acceleration associated with noninertial coordinates [recall Fig. 3.12 and the Coriolis term
V in Eq. (3.48)]. The output of the meter is directly proportional to mass flow.
Figure 6.36 is a schematic of a Coriolis device, to be inserted into a piping system.
The flow enters a double-loop, double-tube arrangement which is electromagnetically vibrated at a high natural frequency (amplitude 1 mm and frequency 100 Hz). The up
flow induces inward loop motion, while the down flow creates outward loop motion, both
due to the Coriolis effect. Sensors at both ends register a phase difference which is proportional to mass flow. Quoted accuracy is approximately 0.2 percent of full scale. Laminar flow element. In many, perhaps most, commercial flowmeters, the flow | v v through the meter is turbulent and the variation of flow rate with pressure drop is nonlinear. In laminar duct flow, however, Q is linearly proportional to p, as in Eq. (6.44):
Q [ R4/(8 L)] p. Thus a laminar flow sensing element is attract...
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- Spring '08