S

Sievert

H = D × w_R
Quick Reference
Formula / NotationH = D × w_R
Also Known AsEquivalent dose unit, effective dose unit, Sv, rem (older unit: 1 Sv = 100 rem)

What is Sievert?

The sievert (Sv) is the SI unit of effective radiation dose — the measure of the biological effect of ionizing radiation on human tissue. It accounts not only for the absorbed dose (gray, Gy) but also for the biological effectiveness of different types of radiation through a radiation weighting factor (wR). 1 Sv = 1 J/kg (of equivalent dose). The sievert is used in radiation protection to assess health risk.

Formula & Notation

H = D × w_R

Other Names / Synonyms: Equivalent dose unit, effective dose unit, Sv, rem (older unit: 1 Sv = 100 rem)

Properties & Characteristics

H (Sv) = D (Gy) × w_R. Radiation weighting factors: gamma/X-ray/beta: wR = 1. Neutrons: wR = 5–20 (energy dependent). Alpha particles: wR = 20. Protons: wR = 2. Dose limits: occupational workers: 20 mSv/year (averaged). General public: 1 mSv/year. Background radiation: ~2–3 mSv/year. Lethal dose LD50: ~4–5 Sv (whole body, acute).

Uses & Applications

Radiation protection dose limits (ICRP recommendations). Occupational dosimetry for radiation workers. Medical radiation dose assessment. Nuclear accident dose reconstruction. Radiation therapy planning (radiobiology). Environmental radiation monitoring.

Safety Information

Unit used in radiation safety — understanding dose limits prevents radiation injury. Acute radiation syndrome: >1 Sv whole body. Lethal dose: 4–5 Sv LD50. Chronic low-dose: stochastic cancer risk. Proper dosimetry essential for radiation worker protection.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Sievert
Formula H = D × w_R
Synonyms Equivalent dose unit, effective dose unit, Sv, rem (older unit: 1 Sv = 100 rem)

Frequently Asked Questions

The sievert (Sv) is the SI unit of effective radiation dose — the measure of the biological effect of ionizing radiation on human tissue. It accounts not only for the absorbed dose (gray, Gy) but also for the biological effectiveness of different types of radiation through a radiation weighting factor (wR). 1 Sv = 1 J/kg (of equivalent dose). The sievert is used in radiation protection to assess health risk.

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