Are Ear Thermometers Accurate for Adults?

Anatomy of the Human Ear
Anatomy of the Human Ear

Are Ear Thermometers Accurate for Adults? In general yes, Ear Thermometers are very accurate for adults, if used correctly. These thermometers, also known as Tympanic Thermometers measure the temperature of the Tympanic Membrane that is positioned at the end of the Auditory Canal.

Normal Ear Temperature

The average normal Tympanic temperature is between 99.1ºF and 99.6ºF ( or 37.3ºC to 37.6ºC ).

Tympanic temperatures of 100.4F ( 38ºC ) or higher, are considered abnormal and signify a Fever.

Particularities and Counter Indications

  • Ear Thermometers need to have a clear field of view to the Tympanic Membrane, which make them positioning sensitive.
  • They are not indicated for newborns and small children with less than one year old as their External Auditory Canal is too small, making it difficult to have a clear field of view to the Tympanic Membrane.
  • A small External Auditory Canal increases the probability of inaccurate readings by performing the measurement on the wall of the Inner Ear Canal.
  • The existence of Ear Wax is also a factor that can make it difficult to have a clear field of view to the Tympanic Membrane. It is very important to have a clear Ear Canal.
  • Ear infections are a factor that increase the probability of inaccurate measurements:
    • Ear Infections can lead to inflammations that will make it more difficult to have a clear field of view to the Tympanic Membrane
    • Ear Infections can lead to inflammations that will increase the temperature of the overall Ear, and Tympanic Membrane, leading to a measurement that does not represent the overall temperature of the body.
  • Ear Temperature measurement should be performed without any movement as this can lead to inaccurate readings.

How to correctly use an Ear Thermometer

As with any medical equipment, manufacturer instructions and directions should be followed at all times to account for particularities of specific Ear Thermometers.

Ear Thermometer Placement
Ear Thermometer Placement

That said, these are the normal steps for using an Ear Thermometer and explanation of each step:

1- Make sure the Ear is clean and there is no excess wax

2- Prepare the Ear Thermometer by removing covers, and placing throw-away tip if applicable for your specific Ear Thermometer

3- Gently, slightly pull Ear upwards, which will position the External Auditory Canal straight

4- Place the Ear Thermometer tip inside the Ear, gently and without forcing or pushing. The Ear Thermometer tip should not be touching the Tympanic Membrane as that would cause damage and be painful.

5- Press the measurement button on the Ear Thermometer and wait until the Ear Thermometer signals that the measurement is complete.

6- Remove the Ear Thermometer from the Ear.

Technically Speaking, how do Ear Thermometers work?

Ear Thermometers are infrared thermometers at their core. So, unlike Regular Digital Thermometers or old Glass Mercury Thermometers where a sensor or device must be in contact with the skin, the Ear Thermometer does not requite contact with the sensor. It does however depend on good positioning for an accurate reading.

Ear Thermometers measure the thermal radiation emitted by the Tympanic Membrane.

Through the measure of the emitted thermal radiation, that all bodies emit, a temperature is inferred taking into account the expected emissivity of the Tympanic Membrane.

So technically speaking, an Ear Thermometer does not directly measure temperature, but instead the thermal radiation, and then a temperature is determined. They are Thermal Radiation Thermometers.

Leave a Reply

Your email address will not be published. Required fields are marked *