--- metadata: title: CIPM, 1988 date: '1988-01-01' source: BIPM - Pavillon de Breteuil resolutions: - dates: - '1988-01-01' title: Representation of the volt by means of the Josephson effect identifier: 1 url: https://www.bipm.org/en/CIPM/db/1988/1/ approvals: - type: affirmative degree: unanimous message: |- + The Comité International des Poids et Mesures considerations: - type: recognizing date_effective: '1988-01-01' message: acting in accordance with instructions given in Resolution 6 of the 18th Conférence Générale des Poids et Mesures concerning the forthcoming adjustment of the representations of the volt and the ohm, - type: considering date_effective: '1988-01-01' message: considering that a detailed study of the results of the most recent determinations leads to a value of stem:[483 597.9 "GHz"/"V"] for the Josephson constant, stem:[K_("J")], that is to say, for the quotient of frequency divided by the potential difference corresponding to the stem:[n = 1] step in the Josephson effect, - type: considering date_effective: '1988-01-01' message: considering that the Josephson effect, together with this value of stem:[K_("J")], can be used to establish a reference standard of electromotive force having a one-standard-deviation uncertainty with respect to the volt estimated to be 4 parts in stem:[10^(7)], and a reproducibility which is significantly better, - type: considering date_effective: '1988-01-01' message: is of the opinion that no change in this recommended value of the Josephson constant will be necessary in the foreseeable future, and actions: - type: recommends date_effective: '1988-01-01' message: recommends that stem:[483 597.9 "GHz"/"V"] exactly be adopted as a conventional value, denoted by stem:[K_(J-90)] for the Josephson constant, stem:[K_("J")], - type: recommends date_effective: '1988-01-01' message: recommends that this new value be used from 1 January 1990, and not before, to replace the values currently in use, - type: recommends date_effective: '1988-01-01' message: recommends that this new value be used from this same date by all laboratories which base their measurements of electromotive force on the Josephson effect, and - type: recommends date_effective: '1988-01-01' message: recommends that from this same date all other laboratories adjust the value of their laboratory reference standards to agree with the new adopted value, - type: calls upon date_effective: '1988-01-01' message: draws the attention of laboratories to the fact that the new value is greater by stem:[3.9 "GHz"/"V"], or about 8 parts in stem:[10^(6)], than the value given in 1972 by the Comité Consultatif d'Électricité in its Declaration E-72. - dates: - '1988-01-01' title: Representation of the ohm by means of the quantum Hall effect identifier: 2 url: https://www.bipm.org/en/CIPM/db/1988/2/ approvals: - type: affirmative degree: unanimous message: |- + The Comité International des Poids et Mesures, considerations: - type: recognizing date_effective: '1988-01-01' message: "*acting* in accordance with instructions given in cgpm-resolution:en/18/6[Resolution 6] of the 18th Conférence Générale des Poids et Mesures concerning the forthcoming adjustment of the representations of the volt and the ohm," - type: considering date_effective: '1988-01-01' message: considering that most existing laboratory reference standards of resistance change significantly with time, - type: considering date_effective: '1988-01-01' message: considering that a laboratory reference standard of resistance based on the quantum Hall effect would be stable and reproducible, - type: considering date_effective: '1988-01-01' message: considering that a detailed study of the results of the most recent determinations leads to a value of 25 812.807 Ω for the von Klitzing constant, stem:[R_("K")], that is to say, for the quotient of the Hall potential difference divided by current corresponding to the plateau stem:[i = 1] in the quantum Hall effect, - type: considering date_effective: '1988-01-01' message: considering that the quantum Hall effect, together with this value of stem:[R_("K")], can be used to establish a reference standard of resistance having a one-standard-deviation uncertainty with respect to the ohm estimated to be 2 parts in stem:[10^(7)], and a reproducibility which is significantly better, - type: considering date_effective: '1988-01-01' message: "*is of the opinion* that no change in this recommended value of the von Kiltzing constant will be necessary in the foreseeable future." actions: - type: recommends date_effective: '1988-01-01' message: recommends that 25 812.807 Ω exactly be adopted as a conventional value, denoted by stem:[R_(K-90)], for the von Klitzing constant, stem:[R_("K")], - type: recommends date_effective: '1988-01-01' message: recommends that this value be used from 1 January 1990, and not before, by all laboratories which base their measurements of resistance on the quantum Hall effect, - type: recommends date_effective: '1988-01-01' message: recommends that from this same date all other laboratories adjust the value of their laboratory reference standards to agree with stem:[R_(K-90)], - type: recommends date_effective: '1988-01-01' message: recommends that in the use of the quantum Hall effect to establish a laboratory reference standard of resistance, laboratories follow the most recent edition of the technical guidelines for reliable measurements of the quantized Hall resistance drawn up by the Comité Consultatif d'Électricité and published by the Bureau International des Poids et Mesures, and