In X-ray equipment operating at 200 mA or higher, the utilization of a specific meter becomes essential to accurately record the mA·S (milliampere-seconds) at a slower needle movement, ensuring convenient readability for exposures below 1/10 second. This particular meter is designed to measure tube current and is employed alongside impulse and electronic timers. However, for exposures exceeding 1/10 second, a standard milliammeter can effectively register the correct milliamperage.