Removable Contamination Efficiencies and MDAs for Commonly Used Radiation Detection Equipment Integrated over 1-Minute Count Time for 225Ac
| MDA | ||||
|---|---|---|---|---|
| Instrument | Background (cpm) | Efficiency (cpm/dpm) | dpm | Bq |
| Portable survey meters | ||||
| α-probe (ZnS) | 0 | 0.07 | 3 | 0.05 |
| Thin window β-/γ-probe (GM) | 33 | 0.18 | 147 | 2.47 |
| Low-energy γ-probe (NaI) | 234 | 0.06 | 1,128 | 18.82 |
| Radiometric detectors | ||||
| Liquid scintillation counter | 36 | 0.97 | 13 | 0.22 |
| γ-counter | 288 | 0.13 | 547 | 9.13 |
cpm = counts per minute; dpm = disintegrations per minute.