Experimental verification of a Monte-Carlo simulation of the gas density in a vacuum chamber

An investigation was performed to check the results of a Monte-Carlo simulation of the gas density variations inside a vacuum chamber used for calibration purposes. The simulations revealed variations of up to 0.33% between gas densities at different calibration gauge ports. In total seven spinning rotor gauges were used to detect the differences experimentally. The mean values of the differences that could be determined with an uncertainty of 0.1% of the mean gas density only are consistent with the results of the Monte-Carlo simulation and give confidence in the simulation overall.