How to Test a Rectal Thermometer

Clean the rectal thermometer before and after use.

Rectal thermometers are most often used to take the temperature of infants. This is because it is difficult to keep an oral thermometer in the right place, and there is a chance the infant may bite down and shatter the thermometer. Accuracy is important, but most inexpensive thermometers will have minor discrepancies. Once you have tested your rectal thermometer, you can take the margin of error into account.

Things You'll Need

• Cooking pot
• Stove

Instructions

1. Fill a cooking pot with water and place it on a stove.

2. Turn the stove burner to high and wait for the water to boil.

3. Hold the thermometer bulb in the water without letting it touch the pot. Water boils at 212 degrees Fahrenheit, which is what your thermometer should read after a few moments. If the thermometer is inaccurate, note how many degrees it is off and make a mental adjustment during future usage.

Tips & Warnings

• Allow the thermometer to cool before use.

References

• Virtual Weber Bullet: Testing Thermometers For Accuracy