A sample taken by wiping a standard area, usually 100 square centimetres, with a paper disc or cloth and counting it in a detector. Results are reported in disintegrations per minute per 100 cm2 and show removable, not fixed, contamination. Large-area wipes with a cloth or mop head give a quick screen of a floor. Smears are the basis for posting and releasing areas and for releasing items from controlled areas.
Take a smear every metre along the trench and bring them back to the counting room.
Also heard as
- swipe
- wipe
Related terms
Removable contamination
Radioactive contamination that can be transferred by wiping or touching, as opposed to fixed contamination.
Contamination
Radioactive material in a place it is not wanted, such as on surfaces, skin, clothing or inside the body.
Frisking
Slowly scanning a person or object with a contamination probe to find radioactive material before it leaves an area.
Sealed source
Radioactive material permanently sealed in a capsule so it cannot escape under normal use.