2. Use a cotton swab, glass fiber filter or Waterman paper, wipe an area of ~100 cm². You may moisten the material used for wipe test.

3. Place the wipe to counting vials, add appropriate amount of scintillation cocktail. Also prepare a vial with a clean swab/filter as a control.

4. Count the radioactivity using a liquid scintillation counter.

5. If wipe test for an area is two times higher than the background (control), clean the area and repeat the wipe test for the area.