essen_1953#

L. Essen, Proc. Phys. Soc. B 66, 189 (1953)

Source record · Catalogue · Review register

Source kind: measurement

Recorded technique: Microwave cavity resonator (Essen and Froome’s method): the resonant frequency of an invar, copper-plated H019 resonator (Q about 40 000) evacuated and filled with the gas, n being their ratio; waveguide bridge with a source measured to 1 part in 10^8, setting to resonance to 1 part in 10^8; 9200 Mc/s (pp. 2-3). Gases at about 20 C and atmospheric pressure.

Materials in structured entries: D2, H2, He, N2, O2

Dataset quantities: refractivity

Contents: 7 datasets; 0 formulas.

Curation notes#

Values are (n - 1) 10^6 of dry gases at 0 C and 760 mm Hg. Reduction (p. 4): ‘For dry air and its main constituents equation (2) of Essen and Froome (1951) is used as this was established by the experimental work of Barrell and Sears (1939)’ (an empirical real-gas law: O2, N2 density real); ‘the results for the other gases are reduced to S.T.P. by means of the ideal gas formula’ (H2, D2, He: density ideal), the error from the law ‘not likely to be more than 0.02%’.

Frequency: the apparatus ‘was designed to operate at 9200 Mc/s’ (p. 3) and the abstract says 9200 Mc/s, but the table heads the column ‘9000 Mc/s’ (image checked), and so does the Discussion (PDF p. 4): two statements against two; 9200 Mc/s is taken (immaterial here) (vacuum wavelength c/f = 32.586 mm). At this frequency the refractivity of a nonpolar gas is the static one, including the infrared (vibrational) polarizability; oxygen’s also includes its paramagnetism (n^2 = epsilon mu), which the paper does not separate.

Uncertainty: the table’s ‘limits of error’ ‘including systematic errors’ (O2 0.2, N2 0.1, H2 0.2, D2 0.3, He 0.2, x 10^-6) are used as bounds; standard deviations 0.04, 0.04, 0.04, 0.2, 0.03 from 9, 5, 18, 5, 11 measurements. Purities (p. 4): O2 99.5 % (main impurity N2), N2 impurity below 1e-6, H2 99.95 % (N2), He 99.8 % (Ne), ‘corrected for the main impurities and the limits of error allow for their being twice the stated amount’; deuterium from the Clarendon Laboratory in two samples, the first 99.32 % with 0.68 % hydrogen (whether corrected is not said).

Essen and Froome’s (1951) 24 000 Mc/s values of O2 and N2, printed for comparison, are extracted as reproduced (not in the library). Water vapour (60.7 at 20 C, 10 mm Hg) and CO2-free air are not curated species. The H2 and D2 values are 2 % and 3 % above Ishiguro et al.’s (1952) calculations (133.3, 130.8), and helium is 0.4e-6 above the Cuthbertsons’ 34.6 (cuthbertson_1932) (pp. 5-6).

Reproductions: newell_1965’s datasets essen_1953_{He,H2,N2,O2} are these values (with the nominal 9 GHz as frequency), now reproductions of this record.

Recorded bibliographic identity status: VALIDATED_WITH_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents.

Datasets#

essen_1953/microwave_O2#

{
  "id": "microwave_O2",
  "material": "O2",
  "file": "O2/essen_1953__microwave_O2.csv",
  "table": "tbl_648ebcc40786",
  "quantity": "refractivity",
  "scale": 1e-06,
  "abscissa_unit": "m",
  "wavelength_medium": "vacuum",
  "state": "1atm_0C",
  "density": "real",
  "use": "primary",
  "uncertainty": {
    "column": true,
    "level": "bound"
  }
}

Table, present value at 9200 Mc/s (c/f = 32.586 mm, effectively static), 9 measurements, standard deviation 0.04; sigma = the limits of error including systematic errors (+-0.2). Includes the paramagnetic contribution (not separated).

essen_1953/microwave_N2#

{
  "id": "microwave_N2",
  "material": "N2",
  "file": "N2/essen_1953__microwave_N2.csv",
  "table": "tbl_648ebcc40786",
  "quantity": "refractivity",
  "scale": 1e-06,
  "abscissa_unit": "m",
  "wavelength_medium": "vacuum",
  "state": "1atm_0C",
  "density": "real",
  "use": "primary",
  "uncertainty": {
    "column": true,
    "level": "bound"
  }
}

Table, present value at 9200 Mc/s (c/f = 32.586 mm, effectively static), 5 measurements, standard deviation 0.04; sigma = the limits of error including systematic errors (+-0.1).

essen_1953/microwave_H2#

{
  "id": "microwave_H2",
  "material": "H2",
  "file": "H2/essen_1953__microwave_H2.csv",
  "table": "tbl_648ebcc40786",
  "quantity": "refractivity",
  "scale": 1e-06,
  "abscissa_unit": "m",
  "wavelength_medium": "vacuum",
  "state": "1atm_0C",
  "density": "ideal",
  "use": "primary",
  "uncertainty": {
    "column": true,
    "level": "bound"
  }
}

Table, present value at 9200 Mc/s (c/f = 32.586 mm, effectively static), 18 measurements, standard deviation 0.04; sigma = the limits of error including systematic errors (+-0.2).

essen_1953/microwave_D2#

{
  "id": "microwave_D2",
  "material": "D2",
  "file": "D2/essen_1953__microwave_D2.csv",
  "table": "tbl_648ebcc40786",
  "quantity": "refractivity",
  "scale": 1e-06,
  "abscissa_unit": "m",
  "wavelength_medium": "vacuum",
  "state": "1atm_0C",
  "density": "ideal",
  "use": "primary",
  "uncertainty": {
    "column": true,
    "level": "bound"
  }
}

Table, present value at 9200 Mc/s (c/f = 32.586 mm, effectively static), 5 measurements, standard deviation 0.2; sigma = the limits of error including systematic errors (+-0.3). Deuterium 99.32 % (0.68 % H2) in the first sample.

essen_1953/microwave_He#

{
  "id": "microwave_He",
  "material": "He",
  "file": "He/essen_1953__microwave_He.csv",
  "table": "tbl_648ebcc40786",
  "quantity": "refractivity",
  "scale": 1e-06,
  "abscissa_unit": "m",
  "wavelength_medium": "vacuum",
  "state": "1atm_0C",
  "density": "ideal",
  "use": "primary",
  "uncertainty": {
    "column": true,
    "level": "bound"
  }
}

Table, present value at 9200 Mc/s (c/f = 32.586 mm, effectively static), 11 measurements, standard deviation 0.03; sigma = the limits of error including systematic errors (+-0.2).

essen_1953/essen_froome_1951_O2#

{
  "id": "essen_froome_1951_O2",
  "material": "O2",
  "file": "O2/essen_1953__essen_froome_1951_O2.csv",
  "table": "tbl_648ebcc40786",
  "quantity": "refractivity",
  "scale": 1e-06,
  "abscissa_unit": "m",
  "wavelength_medium": "vacuum",
  "state": "1atm_0C",
  "density": "real",
  "use": "reproduced",
  "reproduced_from": [
    "L. Essen and K. D. Froome, Proc. Phys. Soc. B 64, 862 (1951)"
  ],
  "uncertainty": {
    "column": true,
    "level": "not stated"
  }
}

Table, Essen and Froome’s value at 24 000 Mc/s (c/f = 12.491 mm) with their +- (level not stated; newell_1965 reads them as about 2 sigma). Also reproduced by newell_1965 (essen_froome_1951_O2).

essen_1953/essen_froome_1951_N2#

{
  "id": "essen_froome_1951_N2",
  "material": "N2",
  "file": "N2/essen_1953__essen_froome_1951_N2.csv",
  "table": "tbl_648ebcc40786",
  "quantity": "refractivity",
  "scale": 1e-06,
  "abscissa_unit": "m",
  "wavelength_medium": "vacuum",
  "state": "1atm_0C",
  "density": "real",
  "use": "reproduced",
  "reproduced_from": [
    "L. Essen and K. D. Froome, Proc. Phys. Soc. B 64, 862 (1951)"
  ],
  "uncertainty": {
    "column": true,
    "level": "not stated"
  }
}

Table, Essen and Froome’s value at 24 000 Mc/s (c/f = 12.491 mm) with their +- (level not stated; newell_1965 reads them as about 2 sigma). Also reproduced by newell_1965 (essen_froome_1951_N2).

Formulas#

No formulas are recorded.

Corrections#

No dataset errata are recorded in this source record.

Formula corrections, where recorded, appear with their formulas above. Curation notes may also discuss corrections or unresolved interpretation. Consult the review register for the checks and decisions.