Dead Weight Piston Gage

DEAD WEIGHT PISTON GAUGE MALIK MUHAMMAD NASIR BS-CHEMICAL ENGINEERING UNIFERSITY OF GUJRAT,PAKISTAN 1

Dead Weight Piston Gauge manome ter Weigh t suppo weigh ts

BasePlate

Drain valve

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UNIT LAYOUT • The pressure gauge unit • The load unit • The load unit is connected to pressure gauge unit via an oil filled line enabling the manometer to display

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Zero Balance • Press the piston out of the cylinder using a hand wheel • Remove the transport cap • Adjust the oil level in the open cylinder until the cylinder is filled up to the edge • The manometer being tested should now indicate zero, as it is only subject to ambient pressure 4

CALIBRATING THE PRESSURE GAUGE • After checking the zero point of the of the manometer install the weight support into the cylinder of the loadunit • Set the weight support in gentle rotation to avoid static friction • The mass of the support is 385 g. piston diameter is 12mm. • P=.334 bar 5

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ACCURACY CLASS RATING The accuracy class rating describes the maximal percentage difference allowed between the real and measured pressure ,in relation of the end scale value. For an instrument of the quality class 1 the maximum allowed difference is +/-1 % from the end scale value. e.g. Measuring range = 0 – 2.5 bar Accuracy class rating = 1.0 Maximal allowed difference = 0.025 bar

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Address the following points in your lab reports

• What is meant by the drift of an equipment? • Specify the drift on the graph you made • What is meant by the dead weight? • What is Pascal's law? • What is the working principle of hydraulic press? • What is the difference between the hydraulic and pneumatic dead weight calibrator? • What are the possible causes of the 7

Thank you

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