For a desired radiographic density increase from 1.0 to 2.0, what exposure is required if initial exposure was 10 mA-min?

To understand the required exposure for increasing radiographic density from 1.0 to 2.0, one must consider the logarithmic relationship between exposure and density as outlined by the law of characteristic curves in radiography.

Radiographic density is commonly measured on a logarithmic scale, meaning that to achieve a density increase, the exposure must also increase exponentially. Specifically, one density increment requires approximately doubling the exposure. Since the density is increasing from 1.0 to 2.0, which represents a one unit increase (or an increase of 1.0 to a final density of 2.0), the exposure needs not only to be doubled but calculated precisely based on the logarithmic relationship that governs this process.

Using the general formula for density change — where density can be expressed as D = log10(I), with I being the intensity or exposure — one can apply the exposure needed for doubling density. In this scenario, from the starting exposure of 10 mA-min, to achieve a density of 2.0 (which is twice that of 1.0), the necessary exposure becomes calculated as follows:

If an exposure of 10 mA-min yields a density of 1.0, then to achieve a density