THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -Each large square is five small squares in width, and each small square is 1 mm wide and equivalent to 0.04 s. The electrical activity detected by the electrocardiogram machine is measured in millivolts.

Detailed explanation-2: -ECG paper is a grid where time is measured along the horizontal axis. Each small square is 1 mm in length and represents 0.04 seconds. Each larger square is 5 mm in length and represents 0.2 seconds.

Detailed explanation-3: -The ECG grid On the horizontal axis, each large box represents 0.2 seconds at a typical paper speed of 25 mm per second, which is then divided into five smaller boxes that each represent 0.04 seconds.