Final answer:
The intensity of contractions during childbirth is assessed using an internal monitor, which provides accurate measurements of uterine muscle contraction intensity.
Step-by-step explanation:
The nurse is using a monitor to assess the intensity of contractions during childbirth. The type of monitor that will assess the intensity of the contractions is a internal monitor. An internal monitor, unlike an external monitor, is placed inside the cervix and can provide a more accurate measure of contraction strength. It's often used in conjunction with a fetal monitor, which tracks the baby's heart rate, or a maternal monitor, which checks the mother's vitals. The internal monitor is specifically designed to gauge uterine muscle contraction intensity.