In the mAs parameter, what does the 's' represent?

In the mAs parameter, what does the 's' represent?

• A. Time/length of exposure
• B. The current
• C. The tube voltage
• D. The film speed

Answer: (A)

The 's' represents seconds, the exposure time. In mAs, milliampere-seconds, you multiply the tube current (mA) by the exposure duration (seconds) to get the total charge and thus the total number of X-ray photons produced during the exposure. This quantity controls how much radiation reaches the film, increasing with longer exposure times. It is not the current (mA), nor the tube voltage (kVp), nor the film speed, which is a property of the receptor rather than the exposure.

The 's' represents seconds, the exposure time. In mAs, milliampere-seconds, you multiply the tube current (mA) by the exposure duration (seconds) to get the total charge and thus the total number of X-ray photons produced during the exposure. This quantity controls how much radiation reaches the film, increasing with longer exposure times. It is not the current (mA), nor the tube voltage (kVp), nor the film speed, which is a property of the receptor rather than the exposure.