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O2-A3 Alphasense 25% 3 Year Oxygen Smart EC Sensor

Alphasense 25% Oxygen Smart EC Sensor - CO2 Meter
Regular price $82.00

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The O2-A3 Alphasense Oxygen Sensor (formerly known as the AP-0004) is a plug-in replacement sensor for hand-held gas detectors that use an O2-A3 sensor. Gaining precise oxygen measurement is critical for industries that require its use for safety, medical, air quality or specialized process.

It is important to verify the sensor you are replacing has an AlphaSense O2-A3 printed on the side before ordering. Due to our low prices we cannot accept returns for the wrong sensor.


  • 0.1 to 20.9% oxygen sensor
  • Does not require calibration
  • Up to 3 year lifespan
  • Small, compact and maintenance free
  • Measurement Range: 0.1-20.9% Oxygen
  • Output @ 20.9% Oxygen: 60-85 uA
  • Output @ 0% O2: < 2.5 uA
  • Response Time: < 15 sec. t90 (s) from 20.9% to 0%
  • Linearity: 0.6% O2 deviation @ 10%
  • Output drift: < 1% change @ 3 months
  • Operating life: > 36 months until 85% original Output of 20.9%


  • Dimensions (sensor): 17.4mm x 20.3mm


  • 90 days. See CO2Meter Terms and Conditions

* Oxygen O2 Sensor Pin Sockets - Manufacturers do not recommend soldering to the pins. Pin sockets can be purchased from Andon distributors. Click here to search for your sensor's socket. Select the brand PDF, find your sensor, then search for the Andon part number for your sensor's socket.

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Customer Reviews

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"Easy to install, easy to set up, and easy calibration - just what I was looking for."

- Phillip Farrar
Water Plant Superintendent

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