NDT unit converter

Activity, dose, length, pressure, velocity and temperature conversions used in NDT.

For reference only — verify against your procedure and the governing code.

Quantity

Value

From

Result

curie (Ci): 0.027027
millicurie (mCi): 27.027
becquerel (Bq): 1.00000e+9
megabecquerel (MBq): 1,000
terabecquerel (TBq): 0.001

Formula

1 Ci = 3.7 × 10¹⁰ Bq = 37 GBq (exact)
1 rem = 0.01 Sv = 10 mSv; 1 rad = 0.01 Gy (exact)
1 R ≈ 1 rem for X- and gamma radiation (approximation)
1 in. = 25.4 mm (exact); 1 psi = 6.894757 kPa
°C = (°F − 32) / 1.8

Units. Lists every unit in both systems; the switch picks which one the converter starts from.

Assumptions and limits

Roentgen measures exposure in air, not dose. Converting it to rem or sieverts treats 1 R as 1 rem — an approximation for gamma and X-rays only.

Sources

NIST Special Publication 811, Guide for the Use of the International System of Units, Appendix B conversion factors.
10 CFR Part 20 (eCFR, current): 20.1003 definition of high radiation area; 20.1004 units and quality factors; 20.1301(a)(2) dose in any unrestricted area.
U.S. NRC Training Center, "Industrial Radiography Health Physics Review" (NRC ADAMS ML12146A259) — gamma constants (slide 23), inverse square law (slide 24), half-value-layer rules of thumb (slide 14), 1 Ci = 37 GBq (slide 17).

For reference only — verify against your procedure and the governing code.

Standards and documents are cited by their publishers' names to identify them. TRACE is not affiliated with, endorsed by or sponsored by ASTM International, ASME, the U.S. Nuclear Regulatory Commission, NIST or the Laboratoire National Henri Becquerel. Formulas are paraphrased and cited by clause; get the documents themselves from their publishers.