Moly Flow..er Plus : program komputerowy do badania parametrów stanu gazu w układach metrologicznych bardzo wysokiej próżni

The dynamic expansion of gas is widely used method in the pressure (or the gas number density) standards. The accuracy of the standard depends, among the others, upon the accuracy of calculating the conductance and demands the ununiformities of the gas number density and of the gas flux distributions inside the calibration chamber. Usually during calculation of conductance one assumes the uniform distribution of the molecules at the entrance plane to the orifice system as well as cosine distribution of molecule direction vs. normal to this plane. Many works shows that it is not truth. Moly Flow..er Plus is the software, been development specially for research the parameters of gas flow in metrological systems. It uses Monte-Carlo method for calculating: gas flux distribution and angular distribution inside the calibration chamber and also the time of flight method for conductance of orifice. In this way the chamber shape influence on conductance can be found. Moly Flow..er Plus is full 32-bit program working under Windows 95/98 NT operating system with graphical user interface. In Monte-Carlo simulation, the quality of RNG highly influenced the results of simulation especially if high precision of this process is needed, so there is the possibility to choose Random Number Generator from 5 high quality generators implemented in the program. Program was used in many control application tests connected with comparison the simulation results with the values of Clausing factors for spherical cylindrical and conical elements. All the simulation results were well below 2s interval.