This page documents an OPTIMADE Unit Definition. See https://schemas.optimade.org/ for more information.
ID: https://schemas.optimade.org/defs/v1.2/units/si/1970/temporary/roentgen
Definition name: roentgen
Unit name: roentgen
Latin symbol: R
Display symbol: R
Description: A unit used to express the exposure of ionizing radiation defined as 2.58 x 10⁻⁴ C/kg using the 1967 SI units.
The roentgen unit appears in the International System of Units (SI), 1st ed. (1970) defined as "1 R = 2.58 x 10⁻⁴ C/kg" with the footnote: "The roentgen is a special unit used to express the ionization exposure of ionizing radiation."
Resources:
JSON definition:
{
"$id": "https://schemas.optimade.org/defs/v1.2/units/si/1970/temporary/roentgen",
"$schema": "https://schemas.optimade.org/meta/v1.2/optimade/physical_unit_definition.json",
"title": "roentgen",
"symbol": "R",
"display-symbol": "R",
"description": "A unit used to express the exposure of ionizing radiation defined as 2.58 x 10\u207b\u2074 C/kg using the 1967 SI units.\n\nThe roentgen unit appears in the International System of Units (SI), 1st ed. (1970) defined as \"1 R = 2.58 x 10\u207b\u2074 C/kg\" with the footnote: \"The roentgen is a special unit used to express the ionization exposure of ionizing radiation.\"\n\n- The International System of Units (SI), 1st ed. (1970) categorizes the unit as \"Units in use temporarily with the International System.\"\n- The International System of Units (SI), 2nd ed. (1973) rephrases the footnote to: \"The roentgen is a special unit used to express the exposure of X or gamma radiation.\"\n- The International System of Units (SI), 7th ed. (1998) changes the categorization to \"Examples of other non-SI units\".\n- The International System of Units (SI), 8th ed. (2006) omits the unit.",
"resources": [
{
"relation": "Definition in the International System of Units (SI), 1st Edition",
"resource-id": "https://www.bipm.org/en/publications/si-brochure"
},
{
"relation": "Wikipedia article describing the unit",
"resource-id": "https://en.wikipedia.org/wiki/Roentgen_(unit)"
}
],
"defining-relation": {
"base-units": [
{
"symbol": "C",
"id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/coulomb"
},
{
"symbol": "kg",
"id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/kilogram"
}
],
"base-units-expression": "C*kg^-1",
"scale": {
"numerator": 258,
"exponent": -6
}
},
"x-optimade-definition": {
"label": "roentgen_si_1970_temporary",
"kind": "unit",
"format": "1.2",
"version": "1.2.0",
"name": "roentgen"
}
}