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rcd-c3-durchfluss.png: Venturi Nozzle-Differential Pressure RCD-..C3

Venturi Nozzle-Differential Pressure RCD-..C3

Measuring / switching range:
0.5 - 3.3 ... 300 - 2300 l/min water
0.5 - 5.35 ... 300 - 2750 Nm³/h air
Connection: G ½ ... G3, ½ ... 3" NPT
Material: aluminum bronze, stainless steel
pmax: PN40
tmax: 100°C
Accuracy: ±3 % of full scale
Analogue output, contacts NPN / PNP, digital indicator


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The KOBOLD flow meter model RCD is used for measuring and monitoring liquid and gas flows. The device works on the well-known principle of the Venturi nozzle. A small pressure difference proportional to the flow is produced by the flowing medium at an orifice constriction (nozzle) in the device housing. The shape of the nozzle is based on the flow, whereby the flow characteristic remains constant over the entire measuring range.

Drill holes are located in the housing fitting to absorb the resulting differential pressure and transfer it to a differentialressure measuring cell fitted in the housing. If the flow is exceeded the differential pressure measuring cell is protected by locking pins. On mechanical displays the flow rate measured by the  pressure measuring cell is transferred via a pointer movement to the pointer indicator calibrated in l/min water or Nm 3 /h air.

On electronic displays the mechanical motion is converted to an electrical signal by a Hall-sensor. Various electronic modules are then used to display and monitor the volumetric flow. Special scales are available for all media at any pressure and any temperature.

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