Development of a primary standard for dynamic pressure based on drop weight method covering a range of 10 MPa–400 MPa

Abstract

In this paper we present the development of a primary standard for dynamic pressures that is based on the drop weight method. At the moment dynamic pressure transducers are typically calibrated using reference transducers, which are calibrated against static pressure standards. Because dynamic and static characteristics of pressure transducers may significantly differ from each other, it is important that these transducers are calibrated against dynamic pressure standards. In a method developed in VTT Technical Research Centre of Finland Ltd, Centre for Metrology MIKES, a pressure pulse is generated by impact between a dropping weight and a piston of a liquid-filled piston-cylinder assembly. The traceability to SI-units is realized through interferometric measurement of the acceleration of the dropping weight during impact, the effective area of the piston-cylinder assembly and the mass of the weight. Based on experimental validation and an uncertainty evaluation, the developed primary standard provides traceability for peak pressures in the range from 10 MPa to 400 MPa with a few millisecond pulse width and a typical relative expanded uncertainty (k = 2) of 1.5%. The performance of the primary standard is demonstrated by test calibrations of two dynamic pressure transducers.

Improvement of dynamic pressure standard for calibration of dynamic pressure transducers

“…Mass is the total mass of dropping mass, the mass of piston and mass of fluid under operation. Acceleration of the dropping mass is calculated as the addition of two acceleration values they are local gravity of acceleration value and acceleration of dropping mass [3]. Acceleration of the dropping mass is measured by a laser interferometer system from three different points of dropping mass as seen in figure 5.…”

Measurement uncertainty of a measurement system for dynamic pressure in the kbar regime

“…Dynamic measurements of pressure play a key role in manufacturing, process control, product testing, internalcombustion engines, and in safety-related measurements [1][2][3][4][5][6][7][8]. For instance, to ensure the safety of the user of powderactuated tools or firearms the maximum safe pressure during firing of the tool or gun must not be exceeded.…”

On using converging shock waves for pressure amplification in shock tubes

“…Among the few available dynamic calibration methods [7,11], the most notable are the shock tube [12,13] and the drop weight [14,15] methods. Both are aperiodic single pressure pulse generators.…”