Melabinc.docx

Egnal, Arturo Jr. R

Engr. Jason T. Repiso

BSME

ME Laboratory 1

1.) What basic methods are used for calibration of flow measurement devices?  Standing start and stop method – this method is generally preferred for meters measuring exact quantities of liquid, especially meters for batch measurements.  Flying start and finish method or diverter method – a method where the flow through the meter is not stopped but continues uninterrupted.  Gravimetric Calibrators – a flow meter can be calibrated gravimetrically by weighing the quantity of liquid collected in a vessel.  Volumetric Calibrators – the measurement of the quantity of liquid collected may be carried out volumetrically by collecting a known volume of liquid in a container. 2.) What is meant by positive-displacement flow meter? - It measures the volumetric flow of fluids in pipes, such as water, hydrocarbons, cryogenic liquids, and chemicals. 3.) What are the relative advantages of the venture, orifice, and flow nozzle meters?  They have a simple construction.  They can installed in inclined position.  They are inexpensive.  They can easily maintained. 4.) What is a sonic nozzle? How is it used? What are its advantage and disadvantage? - A sonic nozzle consists of a smooth rounded inlet section converging to a minimum throat area and then diverging along a pressure recovery section or exit cone. - It is used by pressurizing the inlet or evacuating the exit, to achieve an inlet/outlet pressure ratio of 1.4 to 1 or greater. This ratio maintains the Nozzle in a “choked” or “sonic” state. Advantage;  Internationally recognized flow meters  Mass Flow varies linearly with inlet pressure  Minimum upstream piping required  Long term accuracy  Excellent repeatability  No moving parts  Differential pressure measurement not required  Flow rate is not affected by downstream flow disturbances  Mass flow is constant with varying downstream pressure 5.) Why is a rotameter is called a drag meter? Could it also be called an area meter? - Rotameter is a device that measures the flow rate of liquid or gas in a closed tube. Sometimes it is called drag meter because there’s a drag force acting upwardly inside in a tube due to fluid flow. - It can be named as area meter due to the flow measurement in cross-sectional area.