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/1981/temporary/rem**

`rem`

**Unit name:** Roentgen equivalent man

**Latin symbol:** rem

**Display symbol:** rem

**Description:** The "roentgen equivalent man" (rem) is a unit used in radioprotection meant to represent a dose of any ionizing radiation comparable in effect to one roentgen of high-voltage x-radiation, taken to be equal to 10⁻² Sv using the 1967 SI units.

The rem unit appears in the International System of Units (SI), 4th ed. (1981) defined as "1 rem = 1 cSv = 10⁻² Sv" with the footnote: "The rem is a special unit used in radioprotection to express the equivalent dose."

**Resources:**

- Definition in the International System of Units (SI), 4th Edition
- Wikipedia article describing the unit

**JSON definition:**

```
{
"$id": "https://schemas.optimade.org/defs/v1.2/units/si/1981/temporary/rem",
"$schema": "https://schemas.optimade.org/meta/v1.2/optimade/physical_unit_definition.json",
"title": "Roentgen equivalent man",
"symbol": "rem",
"display-symbol": "rem",
"description": "The \"roentgen equivalent man\" (rem) is a unit used in radioprotection meant to represent a dose of any ionizing radiation comparable in effect to one roentgen of high-voltage x-radiation, taken to be equal to 10\u207b\u00b2 Sv using the 1967 SI units.\n\nThe rem unit appears in the International System of Units (SI), 4th ed. (1981) defined as \"1 rem = 1 cSv = 10\u207b\u00b2 Sv\" with the footnote: \"The rem is a special unit used in radioprotection to express the equivalent dose.\"",
"resources": [
{
"relation": "Definition in the International System of Units (SI), 4th 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_equivalent_man"
}
],
"defining-relation": {
"base-units": [
{
"symbol": "kg",
"id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/kilogram"
},
{
"symbol": "m",
"id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/metre"
},
{
"symbol": "s",
"id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/base/second"
}
],
"base-units-expression": "kg*m^2*s^-2",
"scale": {
"exponent": -2
}
},
"x-optimade-definition": {
"label": "rem_si_1981_temporary",
"kind": "unit",
"format": "1.2",
"version": "1.2.0",
"name": "rem"
}
}
```