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

D−FL 100 Seite 9If the differential pressure transducer cannot be installed higher than the measuring differential pressurebar, at least the first part of the supply line should angle upward to the differential pressure transducer,so that the condensation can flow back to the differential pressure bar in this area.The auxiliary current of the differential pressure transducer is 11 to 30 VDC and is supplied by the D-FL100-10 Display (24 VDC). Please consult the operating manual for further details.3.3. D-FL 100-10 DisplayThe D-FL 100-10 Display evaluates the measuring signal from the differential pressure transducer underdifferent application conditions. Gas velocity is usually evaluated under operating conditions. If acomparison of the volume or mass flow to standard values is desired, further gas flow parameters mustbe provided to the D-FL 100-10 Display. Connections for temperature and pressure sensors areavailable for this purpose.A current signal of 4 to 20 mA is available as an output proportional to the volume or mass flow. It canbe connected to additional evaluation devices, such as the emissions D-FL 100-10 Display, recorder ora DAS. The current measured value is shown on a display. Parameters such as inner stack diameter,standard density, c-factor and measuring ranges are programmed on site.The D-FL 100-10 Display consists of a 19-inch rack mount (width 21 TE; height 3 HE) with its owndisplay. If no cabinet is available, the unit can be delivered with a plastic wall housing (24 TE).There are two signals to indicate that the set limit values have been exceeded, and an additional signalfor the status “maintenance/measuring.”Four keys are used to operate the evaluator: MOD, STO, , . The MOD key leads to the setting modeand illuminates the upper yellow indicator light. By pressing the key, the desired function (shown inthe following chart) is selected and the respective LED will be illuminated. The stored values of thecorresponding function are shown on the display. If the value does not need to be changed, press theMOD key once more to exit the setting mode. To change the value, press the STO key. The four-digitdisplay will show a blinking digit.This digit can be increased by pressing the key. Choose the next digit by pressing the key.Pressing the STO key transfers the changed value into non-volatile memory (EEPROM). The LEDinside the STO key will switch off, and the saved value will be displayed. The system automaticallydetermines whether a programmed value is larger than 20 mA. If the value is larger than 20 mA, it willnot be saved; the previous value will once again be displayed. The setting mode can be left by pressingthe MOD key. The LED inside the MOD key switches off.Fig. 8 shows the front cover of the D-FL 100-10 Display.GmbH