Suojakerrointa

Suojakerrointa is a Finnish term used to describe a coefficient that expresses the effectiveness of a protective measure or shielding in reducing exposure to a hazard. It is typically defined as the ratio of the level of exposure, dose, or risk without protection to the level with protection. In practice, a higher suojakerrointa indicates stronger protection.

The concept is used across several fields, including radiation protection, acoustics, industrial hygiene, and personal protective equipment assessment. In radiation protection, for example, suojakerrointa may describe how much a shielding material or barrier reduces the dose to a person. In acoustics, it can refer to how effectively hearing protectors or walls attenuate sound. In occupational safety, equipment such as respirators and barriers are assigned protection factors that relate external hazard levels to resultant exposure.

Calculation and interpretation are straightforward in principle: suojakerrointa = exposure without protection / exposure with protection. If exposure would be 100 units without protection but is reduced to 2 units with protection, the suojakerrointa is 50. The concrete value depends on the hazard type, energy or concentration, equipment fit, usage conditions, and duration of exposure.

Standards and terminology vary by field, and the Finnish term often aligns with the English equivalents “protection factor” or “shielding factor.” While the concept provides a useful single-number summary of protective performance, it should be interpreted together with context, including how protection is used in real-world conditions.