The most important uncertainty component of the pressure step signal determined at the end-wall of the shock tube is associated with the uncertainties of the shock wave velocity and the arrival time of the shock front. Both are determined using a time-of-flight method and are therefore greatly affected by the errors in the detected times of the shock wave passages over the side-wall pressure sensors installed along the shock tube. This paper introduces a method for an automated correction of the systematic errors due to non-ideal dynamic response of the side-wall pressure sensors.

Adaptive Monte Carlo procedure given in Supplement 1 to the “Guide to the expression of uncertainty in measurement” (GUM S1) and a modified GUM S1 procedure were applied to reach a prescribed numerical accuracy of the Monte Carlo results for a chosen confidence level. We assess the performance of the adaptive procedures by employing the measurement model that defines differential pressure generated by a pair of pressure balances. A large number of premature calculation terminations when applying the GUM S1 adaptive procedure leads to a low success rate. Applying the modified GUM S1 shows a reduction in premature termination and improves the success rate.

The expansion of the high technology leads to the increasing demands for the calibration services in the extremal pressure ranges, both vacuum and high gauge pressure in liquid medium. The presentation will deal with the second one, focusing on the solution chosen by the Czech Metrology Institute (CMI) to improve its services in the range of gauge pressure from 0.5 GPa to 1 GPa. A new high-pressure standard will be described, and its first evaluation outlined.

This paper investigates different possibilities of measurement and control of pressure in the cryostat filled with liquid nitrogen. Laboratory designed membrane pressure regulator for automatic control of pressure in the range from 0.9 to 1.3 bar gauge in the cryostat is presented. The performance of the special purpose regulator is evaluated through measurement of pressure deviations from set-point value and their effect on thermal conditions in the cryostat. Results are compared to values obtained using manual pressure regulator.

The calibration of a pressure balance implies to determine the values of the zero-pressure effective area A₀ and the pressure distortion coefficient λ that defines the piston-cylinder assembly effective area A_pi. In order to analyze this behavior, this work compares the method of ordinary least squares with the generalized least squares and weighted least squares to calculate the contributions to type A uncertainty, in particular the residual deviation. For this purpose, an interactive application has been built in R- Shiny, which allows for getting the results mentioned.