Equations

mAs

mA x s

Magnification Factor (MF)

SID/SOD

Object Size (OS)

IS/MF

% of Magnification

(IS - OS)/OS x 100

Direct Square Law (Exposure Maintenance Formula)

mAs₁/mAs₂ = (D₁₎²/(D₂)²

Inverse Square Law

x1/x2 = (D₂₎²/(D₁)²

Transformer Law for Voltage

V_s/V_p = N_s/N_p

Transformer Law for Current

I_s/I_p = N_p/N_s

Heat Units

kVp x mA x s x C

C for Single Pulse Generator

1

C for 3 Phase, 6 Pulse Generator

1.35

C for 3 phase, 12 pulse Generator

C for High Freq. Generator

1.45

Max Electrons in Given Shell

2n²

Bit Depth

2ⁿ

Grid Ratio

Height (H)/Distance Between Strips (D)

Grid Conversion

mAs₂ = mAs₁ x GCF₂/GCF₁

Dose Area Product (DAP) (mGy-cm²)

Dose x Field Size

Minification Gain

Input Phosphor Diameter²/Output Phosphor Diameter²

Brightness Gain

Flux Gain x Minification Gain

Flux Gain

Light Photons/X-ray Photons