How do you use rotary thermometer?

To use a rotary thermometer, first ensure it is properly calibrated if necessary. Insert the thermometer probe into the substance you wish to measure, ensuring it is fully immersed but not touching the sides of the container. Rotate the dial to select the desired measurement scale (Celsius or Fahrenheit), and wait for the reading to stabilize before taking the measurement. Finally, remove the thermometer, clean it according to the manufacturer's instructions, and record the temperature.