Which of the following CANNOT be used for measuring pulse rate?

The thermometer cannot be used for measuring pulse rate because it is specifically designed to measure body temperature. It detects thermal energy and displays the temperature in degrees Celsius or Fahrenheit. While it is an essential tool in monitoring a person's health, it does not have the capability to assess heartbeats or detect pulse.

In contrast, a stethoscope can be utilized to listen to heartbeats and measure pulse rates by placing it on the chest or at pulse points. A digital fitness tracker often has built-in sensors to monitor heart rates continuously by detecting blood flow. Similarly, a pulse oximeter measures the oxygen saturation in the blood and typically provides pulse rate information as well, making it useful for assessing both respiratory and heart functions.