A researcher spends time in three areas of an underground laboratory.
The normal background dose rate is 0.20 μSv0.20\ \mu\mathrm{Sv}0.20 μSv per hour.
| Area | Time spent in area | Measured dose rate in μSv\mu\mathrm{Sv}μSv per hour |
|---|---|---|
| entrance tunnel | 1.5 hours | 0.40 |
| testing chamber | 45 minutes | 2.60 |
| control room | 2.25 hours | 0.28 |
Calculate the additional dose, above the dose due to normal background radiation, that the researcher receives during the visit.