Digital Ear Thermometer Adtemp™ 421 by ADC

Digital Ear Thermometer Adtemp™ 421 Tympanic IR Thermometer
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  • Item #: ADC421
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Price $27.50
Digital Ear Thermometer Adtemp™ 421 Tympanic IR Thermometer
includes plastic storage case


This digital thermometer by American Diagnostic Corporation measures infrared energy radiated from the eardrum and the surrounding tissue. This energy is collected through the lens and converted to a temperature value. The measured reading obtained directly from the eardrum (Tympanic Membrane) can ensure the most accurate ear temperature. 

ADC's Adtemp™ 421 features:

  • Measures core temperature instantly from the ear reliably and accurately
  • Range 89.6°F-108°F ± .4°F or 32°C-42.2°C ± .2°C depending on scale selection
  • Probe cover FREE design is less costly and more convenient to use
  • One Touch Operation with a Large 6mm illuminated display is easy to read
  • Compact (5” Long, 1.9 oz.) ergonomic design fits comfortably in operator’s hand and patient’s ear
  • Audible fever alarm at 99.5°F (37.5°C)
  • 12 reading memory
  • Complete with lithium battery, storage/travel case, and operating instructions
  • Meets ASTM E1965-98 standards for accuracy 

Directions for Use: 

1. Press the ON/OFF button. The display is activated to show all segments for 2 seconds.

2. The last measurement reading will be shown on the display automatically for 2 seconds with the M icon.

3. When the °F or °C icon is flashing, a beep sound ismheard and the thermometer is ready for measurement.

4. Straighten the ear canal by pulling the ear up and back to give a clear view of the eardrum.

    • For children under 1 year: Pull the ear straight back.
    • Children aged 1 year to adult: Pull the ear up and back.

5. While gently pulling the ear, insert the probe snugly into the ear canal and press the START button. Release the button and wait for the beep sound. This is the indication that confirms the end of measurement.

6. Remove the thermometer from the ear canal. The display shows the measured temperature.








 Dual (°F/°C)

 Range °F:


 Range °C:


 Accuracy °F:


 Accuracy °C:


 Response Time:

1 sec







 Flex Probe:


 Needs Sheaths:


 Manufacturer Warranty:

 2 Year

 Battery Type:


 Battery Life:

 1000 uses

 Latex Content:




 (153mm x 31mm x 40mm)


 1.87oz (53g)



 Operating Environment:

 41°F-104°F (5°C-40°C)

 Storage Environment:

 -13°F-131°F (-25°C-55°C)


View additional product details about the ADTEMP 421 Digital Ear Thermometer



  • Never immerse this instrument into water or other liquids (not waterproof).
  • Earwax in the ear canal may cause a lower temperature reading. Therefore it is important to ensure the subject's ear canal is clean.
  • If the instrument is not going to be used for a prolonged period the batteries should be removed. 
  • Ensure that children do not use the instrument unsupervised; some parts are small enough to be swallowed. 
  • WARNING: Use of this instrument is not intended as a substitute for consultation with your physician.


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