English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Gas modulation refractometry (GAMOR) is a technique based on adual-Fabry-Perot (FP) cavity (DFPC) for assessment of gas refractivity,density, and pressure that can alleviate significant limitations ofconventional refractometry systems, predominantly those related to drifts.Repeated assessments of the beat frequency when the measurement cavity isevacuated provide conditions under which the methodology is immune to thelinear parts of the drifts in the system, both those from length changes of thecavities and those from gas leaks and outgassing. This implies that thetechnique is solely influenced by the non-linear parts of the drifts. This workprovides a description of the principle behind the GAMOR methodology andexplicates the background to its unique property. Based on simple models of thedrifts of the temperature in the cavity spacer and the residual gas in thereference cavity, this work predicts that a GAMOR system, when used forassessment of refractivity, can sustain significant temperature drifts andleakage rates without being affected by noticeable errors or uncertainties. Thecavity spacer can be exposed to temperature fluctuations of 100 mK over 103 s,and the reference cavity can have a leakage that fills it up with gas on atimescale of days, without providing errors or uncertainties in the assessmentof refractivity that are 3 x 10^(-12), which, for N2, corresponds to 0.01 ppm(parts per million) of the value under atmospheric pressure conditions, andthereby 1 mPa. Since well-designed systems often have temperature fluctuationsand leakage rates that are smaller than these, it is concluded that there will,in practice, not be any appreciable influence from cavity length drifts, gasleaks, and outgassing in the GAMOR methodology.

Gas modulation refractometry (GAMOR) - On its ability to eliminate the influence of drifts