CCM.G-K2, EURAMET.M.G-K2 and SIM.M.G-K1

MEASURAND : Free-fall acceleration
NOMINAL VALUE : 9.81 m/s2

Degrees of equivalence: Dk and expanded uncertainty Uk (k = 2), both expressed in µGal

CCM.G-K2, EURAMET.M.G-K2 and SIM.M.G-K1

MEASURAND : Free-fall acceleration
NOMINAL VALUE : 9.81 m/s2

Degrees of equivalence: Dk and expanded uncertainty Uk (k = 2), both expressed in µGal

CCT.G-K2 EURAMET.M.G-K2 SIM.M.G-K1

Results are presented under A4 printable format in Summary Results (PDF file).

Comparison
Comparison close
CC comparison
Linked comparison
SIM.M.G-K1
Metrology area, Sub-field Mass and related quantities, Gravity
Description Free-fall acceleration
Time of measurements 2016
Status Approved for equivalence
Final Reports of the comparisons
References

SIM.M.G-K1 Registration and progress form

SIM.M.G-K1 Technical Protocol

Measurand Determination of free-fall acceleration corrected for gravimetric Earth tides, atmospheric and polar motion effects at 10 stations at comparison site TMGO, Boulder, CO USA
Comparison type Key Comparison
Consultative Committee CCM (Consultative Committee for Mass and Related Quantities)
Conducted by SIM (Inter-American Metrology System)
Comments

This comparison is to be linked to CCM.G-K1 and CCM.G-K2 via two of the participants

Results published on 21 July 2017
EURAMET.M.G-K2 and SIM.M.G-K1 results are linked to those of CCM.G-K2

Free-fall acceleration

Pilot institute NIST
National Institute of Standards and Technology
United States
Contact person D. Newell

001 301 975 4228
First Name Last Name
wwww@ww.www +356719836 Institute 1 Institute 1 Khmelnitskiy
Pilot laboratory
NIST

National Institute of Standards and Technology, United States, SIM

CENAM

Centro Nacional de Metrologia, Mexico, SIM

LGUL

Laboratory of Geophysics of the University of Luxembourg, Luxembourg, EURAMET

NRC

National Research Council, Canada, SIM

CCM.G-K2, EURAMET.M.G-K2 and SIM.M.G-K1

  • Key comparison CCM.G-K2

MEASURAND : Free-fall acceleration
NOMINAL VALUE : 9.81 m/s2

A weighted least-square adjustement is applied to the set of measurements obtained from absolute gravimeters AG(k) at Stations j, gjk, with standard uncertainty ujk, in order to evaluate the gravity value Gj at each Station j, as well as the offset Dk for absolute gravimeter AG(k), as explained in Section 6.2 "Second and final solution" of the Final Report).
Gj is the key comparison reference value for Station j. Its associated expanded uncertainty (at a 95 % level of confidence) is denoted Uj.
Gj values are given after substraction of 980 960 000 µGal.
The key comparison reference values are defined at the reference height of 1.3 m.

The degree of equivalence of absolute gravimeter AG(k) is given by a pair of terms: Dk and Uk, its expanded uncertainty at a 95 % level of confidence, both expressed in µGal.
  • Key comparison EURAMET.M.G-K2

The linkage of EURAMET.M.G-K2 comparison results to CCM.G-K2 comparison results are made by means of four laboratory absolute gravimeters that have been used in both comparisons, and the linking process is described in the EURAMET.M.G-K2 Final Report.

  • Key comparison SIM.M.G-K1

The linkage of SIM.M.G-K1 comparison results to CCM.G-K2 comparison results was made using the FG5X-216 gravimeter through EURAMET.M.G-K2. Tthe linking process is described in the SIM.M.G-K1 Final Report Section 7.3.

CCM.G-K2, EURAMET.M.G-K2 and SIM.M.G-K1

  • Key comparison CCM.G-K2

MEASURAND : Free-fall acceleration
NOMINAL VALUE : 9.81 m/s2

AG(k) : absolute gravimeter of Laboratory k
Station j : designation of the station where the measurement was carried out
gjk : gravity value at Station j and height Hjk after substraction of 980 960 000 µGal
ujk : combined standard uncertainty declared by Laboratory k

The comparison was performed in 2013
In general, each participant communicated gravity measurements for three of the fifteen stations used

  • Key comparison EURAMET.M.G-K2

Raw measurements from Absolute Gravimeters reported by the participants in EURAMET.M.G-K2 are given in Table 4 on page 8 of the Final Report.
The comparison was performed in 2015.

  • Key comparison SIM.M.G-K1

Raw measurements from Absolute Gravimeters reported by the participants in SIM.M.G-K1 are given in Table 5 on pp. 7-8 of the Final Report.
The comparison was performed in 2016.