Short and long term stability of HP Cs standards including environmental effects

Kalliomäki, K.; Mansten, T.; Mannermaa, J.

doi:10.1049/cp:20040895

Cited by 3 publications

(18 citation statements)

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“…Therefore, the electronic dispersion simulates an additional acceleration within g evaluated from (1). The value {τ ph } in nanoseconds of phase delay τ ph for the analogue signal in RG58 50 Ω coaxial cable was described according to [11] (from figure 1) as…”

Section: Dispersion In Coaxial Cablesmentioning

confidence: 99%

“…The logarithmic model given by equation ( 2) is just an empirically derived model function given in [11]. Nevertheless, we used another model to describe the data pairs (frequency-delay) given in [11] by expressing the phase delay in a simplified form for the skin-effect region as a function of the square root of the value of frequency in MHz and we get values in nanoseconds…”

Section: Dispersion In Coaxial Cablesmentioning

confidence: 99%

“…that are very close to the relation (2) for the frequencies above 2 MHz, as can be seen in figure 1. The difference for lower frequencies can be understood as an uncertainty due to choosing a fitting function, because only one measurement pair (frequency-delay) below 2 MHz can be found in [11]. The group delay in this case is simply (values in the same units)…”

Section: Dispersion In Coaxial Cablesmentioning

confidence: 99%

“…According to [11], the time delay of coaxial cables is affected by air pressure changes or by bending of the cable. Nevertheless, these effects quantified in [11] are below 1% for the cable-wound diameter of 25 cm or for typical air pressure changes at a station. Thus, the effect on g will also be relatively small.…”

Section: Dispersion In Coaxial Cablesmentioning

confidence: 99%

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Effects of impedance mismatch and coaxial cable length on absolute gravimeters

Křen¹,

Pálinkáš²,

Mašika³

et al. 2017

Metrologia

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The systematic effects of absolute gravimeters have to be investigated to fully utilize their capabilities in metrology and geosciences. In Křen et al (2016 Metrologia 53 27-40) we found that for an FG5 gravimeter, even a few meter long coaxial cable used for transmission of fringe signal causes systematic features in residuals and errors at the level of 1-2 µGal. In this paper, we present experimental results and appropriate models to explain the effects that were found to be caused by impedance mismatches of electronic components and dispersion effects in coaxial cables of gravimeters. The experimental results have been obtained for analogue and transistor-transistor logic (TTL) compatible signals in the FG5-215 gravimeter and for a TTL signal in the FG5X-251 gravimeter. We found that dispersion and impedance mismatch effects are similar for both gravimeters. Furthermore, we describe a model of the dispersion that allows an evaluation of the effect/correction for a given range of the free-fall and thus it is also applicable to other gravimeters. The effect of impedance mismatch for the analogue fringe signal is modelled as an effect of the reflected electronic signal on the evaluation of zero-crossings. The applicability of this model for TTL signal is also discussed.

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Section: Dispersion In Coaxial Cablesmentioning

confidence: 99%

Section: Dispersion In Coaxial Cablesmentioning

confidence: 99%

Section: Dispersion In Coaxial Cablesmentioning

confidence: 99%

Section: Dispersion In Coaxial Cablesmentioning

confidence: 99%

See 2 more Smart Citations

Effects of impedance mismatch and coaxial cable length on absolute gravimeters

Křen¹,

Pálinkáš²,

Mašika³

et al. 2017

Metrologia

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“…Besides, technical issues are often the limiting factor for the lifetime of the electron multiplier. At present, the most widely used commercial cesium beam clock, Microsemi 5071A, is based on this scheme and has negligible frequency variation with environmental changes [18]. The fractional frequency stability of the high-performance version reaches 8.5 × 10 −12 τ −1/2 .…”

Section: Introductionmentioning

confidence: 99%

An overview of the optically detected magnetic-state-selected cesium beam clock

Chen

Liu²,

Fan

et al. 2022

Front. Phys.

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Among all kinds of compact cesium beam clocks, the optically detected magnetic-state-selected cesium beam clock (OMCC) combines the advantages of the magnetic state selecting scheme and fluorescence detecting method. This paper presents an overview of the OMCC. Technical issues, noise sources, frequency shifts and improvements of OMCC are reviewed. Finally, the frequency stability of five OMCC is given, which is better than the stability of the high-performance version of Microsemi 5071A.

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On the effect of distortion and dispersion in fringe signal of the FG5 absolute gravimeters

2015

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The knowledge of absolute gravity acceleration at the level of 1 × 10 −9 is needed in geosciences (e.g. for monitoring crustal deformations and mass transports) and in metrology for watt balance experiments related to the new SI definition of the unit of kilogram. The gravity reference, which results from the international comparisons held with the participation of numerous absolute gravimeters, is significantly affected by qualities of instruments prevailing in the comparisons (i.e. at present, FG5 gravimeters). Therefore, it is necessary to thoroughly investigate all instrumental (particularly systematic) errors. This paper deals with systematic errors of the FG5#215 coming from the distorted fringe signal and from the electronic dispersion at several electronic components including cables. In order to investigate these effects, we developed a new experimental system for acquiring and analysing the data parallel to the FG5 built-in system. The new system based on the analogue-to-digital converter with digital waveform processing using the FFT swept band pass filter is developed and tested on the FG5#215 gravimeter equipped with a new fast analogue output. The system is characterized by a low timing jitter, digital handling of the distorted swept signal with determination of zero-crossings for the fundamental frequency sweep and also for its harmonics and can be used for any gravimeter based on the laser interferometry. Comparison of the original FG5 system and the experimental systems is provided on g-values, residuals and additional measurements/models. Moreover, advanced approach for the solution of the free-fall motion is presented, which allows to take into account a non-linear gravity change with height.

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Short and long term stability of HP Cs standards including environmental effects

Cited by 3 publications

References 0 publications

Effects of impedance mismatch and coaxial cable length on absolute gravimeters

Effects of impedance mismatch and coaxial cable length on absolute gravimeters

An overview of the optically detected magnetic-state-selected cesium beam clock

On the effect of distortion and dispersion in fringe signal of the FG5 absolute gravimeters

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