The determination of volume ratios by gas depletion through multiple expansions

Many laboratories within Euramet started a calibration service in medium and high vacuum recently and did not have the opportunity to take part to a comparison before. In order to assess the uncertainty budget and the quality of the measurement of these laboratories, an intercomparison, Euramet 1040 registered as Euramet.M.P-S7, from 0.1 mPa to 0.9 Pa has been organised. The participants are the CMI (Czech republic), EIM (Greece), IMT (Slovenia), INRIM (Italy), IMBIH (Bosnia Herzegovinia) and MIKES (Finland) while METAS (Switzerland) is pilot laboratory. Three laboratories (INRIM, CMI and METAS) involved in this work have a primary definition of the pressure. Two spinning rotor gauges and a control electronic are used as transfer standard. The circulation of the transfer standard is organised as a succession of loops with a measurement by the pilot between each participant. A reference value has been determined based on a weighted mean of the results of the primary laboratories. All the participants have demonstrated their equivalence in the definition of the pressure. This comparison has been used as pilot comparison for the CCM.P-K14 project which covers the same scope with similar transfer standards.

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“…The expansion ratio of each stage has been characterized using the technique by addition as well as by depletion. [5].…”

Section: Metasmentioning

confidence: 99%

Final report on the supplementary comparison, EURAMET.M.P-S7 (EURAMET project 1040) in the pressure range from 1·10⁻⁴ Pa to 0.9 Pa

et al. 2016

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“…The volume can be determined using multiple methods [6][7][8]. Due to the accuracy requirements and handling restrictions for irradiated materials, the gas-expansion method was chosen.…”

Section: Introductionmentioning

confidence: 99%

Improving Experimental Design through Uncertainty Analysis

2023

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In this paper, the development of a fission-gas collecting and physical-analysis-enabling instrument was proposed for small-volume determination. Analysis specifications require a design capable of accurately and repeatably determining volumes in the range of 0.07–2.5 mL. This system relies on a series of gas expansions originating from a cylinder with known internal volume. The combined gas law is used to derive the unknown volumes from these expansions. Initial system designs included one of two known volumes, 11.85 ± 0.34 mL and 5.807 ± 0.078 mL, with a manifold volume of 32 mL. Results obtained from modeling this system’s operation showed that 0.07 mL can be determined with a relative expanded uncertainty greater than 300% (k = 2) for a single replicate, which was unacceptable for the proposed experimental design. Initial modeling showed that the volume connecting the known volume and rodlet, i.e., the manifold volume, and the sensitivity of the pressure sensor were key contributors to the expanded uncertainty of the measured rodlet volume. The system’s design limited the available options for pressure sensors, so emphasis was placed on the design of the manifold volume. The final system design reduced the manifold volume to 17 mL. These changes in design, combined with replicate analysis, were able to reduce the relative expanded uncertainty by ±12% (k = 2) for the 0.07 mL volume.

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“…There are several methods for the accurate determination of volumes of vacuum vessels such as: by measuring absolute volumes: (a) from dimensional measurements and (b) by gravimetric method or by different gas expansion technique [1][2][3][4][5][6]: (a) gas accumulation method, (b) gas depletion method, (c) direct measurement with spinning rotor gauge, by pressure rise method. But, complicated geometries (like pipes, valves, bellows etc.)…”

Section: Introductionmentioning

confidence: 99%

Volume Determination of Vacuum Vessels by Gas Expansion Method

Avdiaj

Šetina

Erjavec

2015

MAPAN

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This paper presents a practical procedure for the determination and precision calibration of the volume ratio and absolute value of the volume of vacuum chamber by using static expansion method. Such systems for calculations of volume ratio consist from two vessels connected via a valve called the expansion valve. For determination of absolute value of the volume we added another volume with simple shape (determined by dimensional measurements). In such systems, under the isothermal conditions, the gas pressure is reduced by the ratio of the small volume to the sum of the first volume (small volume) and second volume. The uncertainty of measurement of the volume ratio and absolute volume is calculated as well. Relative volume calibration is performed with uncertainties below 0.75 %.

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The determination of volume ratios by gas depletion through multiple expansions

Cited by 6 publications

References 7 publications

Final report on the supplementary comparison, EURAMET.M.P-S7 (EURAMET project 1040) in the pressure range from 1·10⁻⁴ Pa to 0.9 Pa

Final report on the supplementary comparison, EURAMET.M.P-S7 (EURAMET project 1040) in the pressure range from 1·10⁻⁴ Pa to 0.9 Pa

Improving Experimental Design through Uncertainty Analysis

Volume Determination of Vacuum Vessels by Gas Expansion Method

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The determination of volume ratios by gas depletion through multiple expansions

Cited by 6 publications

References 7 publications

Final report on the supplementary comparison, EURAMET.M.P-S7 (EURAMET project 1040) in the pressure range from 1·10−4 Pa to 0.9 Pa

Final report on the supplementary comparison, EURAMET.M.P-S7 (EURAMET project 1040) in the pressure range from 1·10−4 Pa to 0.9 Pa

Improving Experimental Design through Uncertainty Analysis

Volume Determination of Vacuum Vessels by Gas Expansion Method

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Product

Resources

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Final report on the supplementary comparison, EURAMET.M.P-S7 (EURAMET project 1040) in the pressure range from 1·10⁻⁴ Pa to 0.9 Pa

Final report on the supplementary comparison, EURAMET.M.P-S7 (EURAMET project 1040) in the pressure range from 1·10⁻⁴ Pa to 0.9 Pa