DESIGN AND PERFORMANCE EVALUATION OF A PRESSURE GAUGE CALIBRATION APPARATUS

Abstract

This paper presents the design and performance evaluation of a pressure gauge calibration apparatus using a Dead-Weight Testing method. Dead-weight tester was designed using solid works. Materials such as stainless steel, brass, plastic, glass and wood with corrosion resistant were used for the fabrication. The apparatus was tested using water of known specific gravity of 998kg/m³ or approximately 1g/cm³ as pressure medium and set of known weights (including that of the piston = 1.0194kg) as the input data. The actual reading (cylinder pressure), Gauge reading (gauge pressure), Absolute Gauge error, and % Gauge error were recorded. Graph of cylinder pressure and gauge pressure were plotted and a straight line graph with a slope of 0.85 was obtained, indicating linear proportionality. The graph of the absolute gauge error and the gauge pressure also gave a positive slope showing that the error increases as the gauge pressure increases. But, at point (47.53kPa, 8.53kPa), the curve shows negative slope and later returns to positive slope. The graph of the percentage error verses gauge pressure gives a negative slope, showing that values with smaller applications of pressure in the cylinder yielded a higher Fig. of % relative error. Considering the relationship between the experimental results analyzed on the pressure gauge and the actual results being measured by adding weight to the cylinder, a calibration of the system can be conducted.

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KEYWORDS:  pressure, piston, calibration, thrust, force, bourdon tube