Measuring Gas Velocity with the D-FL 100 Differential Pressure Bar

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D−FL 100 Seite 63. System Components of the D-FL 100The D-FL 100 measuring system consists of the following components:• differential pressure bar• differential pressure measuring transducer• D-FL 100-10 DisplayFig. 5:Overview of the system componentsGmbH
D−FL 100 Seite 73.1. Differential Pressure BarThe special shape of the differential pressure bar provides a defined separation point for the gas flowaround its edges. This effects constant conditions for measurement in a large speed range.The separation point of the gas flow normally depends on the shape of the differential pressure bar’sedges and on the speed of the gas. If the position of the separation point of the gas flow on thedifferential pressure bar’s edges changes, a whirl will be created behind the differential pressure bar.The area behind the differential pressure bar thus has different pressure areas due to the differentwhirls. However, a constant flow pattern across the entire speed range on the back of the differentialpressure bar is required for a constant reference pressure. This is ensured by the following profile (Fig.6).Fig. 6:Cross section of the differential pressure barThe differential pressure bar has the shape of a tilted square divided into two chambers by an integrateddivider plate. The tips of the integrated divider plate create the differential pressure bar’s edges. Thedouble chamber system transfers the two pressures (impact pressure and reference pressure) outsideto the differential pressure transducer.The correction factor (c-factor) of the differential pressure bar (see Eq. 2) must be calculated taking intoaccount the geometry of the differential pressure bar and the dimensional relation of the differentialpressure bar to the duct/stack cross section. The c-factor is between 0.5 and 0.7, depending on thediameter of the duct/stack.The application of the differential pressure bar and the gas to be measured will determine what itscomposition should be. The standard differential pressure bar is made of stainless steel (material No.1.4571). Other materials, such as stainless steel alloys, are available for extreme conditions (stainlesssteel alloy material No. 1.4539, Hastelloy C 276 material No. 2.4819, Inconel 602 material o. 2.4816).GmbH
Page 1 and 2: 11/07Measuring Gas Velocitywith the
Page 3 and 4: D-FL 100Table of Contents1. Applica
Page 5 and 6: D−FL 100 Seite 11. ApplicationOne
Page 7 and 8: D−FL 100 Seite 3The output signal
Page 9: D−FL 100 Seite 5To prevent residu
Page 13 and 14: D−FL 100 Seite 9If the differenti
Page 15 and 16: D−FL 100 Seite 114. Installation4
Page 17 and 18: D−FL 100 Seite 13Fig. 11:Installa
Page 19 and 20: D−FL 100 Seite 15Fig. 14:Connecti
Page 21 and 22: D−FL 100 Seite 17Fig. 16:Dimensio
Page 23 and 24: D−FL 100 Seite 19250 mm13538,5 18
Page 25 and 26: D−FL 100 Seite 215.2. Start-up of
Page 27 and 28: D−FL 100 Seite 235.3. Error Messa
Page 29 and 30: D−FL 100 Seite 258. Specification
Page 31 and 32: D−FL 100 Seite 27Fig. 20:Probe cr
Page 33 and 34: D−FL 100 Seite 299. Selecting the
Page 35 and 36: D−FL 100 Seite 319.3. Selecting t
Page 37 and 38: D−FL 100 Seite 33DescriptionHose
Page 39 and 40: D−FL 100 Seite 359.6. Illustratio
Page 41 and 42: D−FL 100 Seite 379.6.3. Mounting,
Page 43 and 44: D−FL 100 Seite 39Customer: XYZ da
Page 45 and 46: D−FL 100 Seite 41If we want to pu
Page 47 and 48: D−FL 100 Seite 4311. Measuring Po
Page 49 and 50: D−FL 100 Seite 45GEMEINSAMESMINIS
Page 51 and 52: D−FL 100 Seite 47EG-Konformitäts
Page 53: D-FL 100 Page 1GmbH · Kollaustraß

Measuring Gas Velocity with the D-FL 100 Differential Pressure Bar

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