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AlphaSense O2-A2 Oxygen Sensor

O2-A2 Oxygen Sensor
Regular price $39.00 USD Sale price

Compare at $59.00 USD

POs or wholesale quantity discounts click here

The AlphaSense O2-A2 oxygen sensor is a replacement sensor for hand-held gas detectors that use the O2-A2 sensor.

⭐⭐⭐⭐⭐ - Rated. Read our Reviews!

Verify the sensor you are replacing has AlphaSense O2-A2 printed on the side before ordering. Due to our low prices we cannot accept returns for the wrong sensor.


  • Electrochemical (EC) sensor designed to last for up to 2 years
  • Good pressure and temperature independence
  • Small, compact & maintenance free

Replacement Oxygen Sensor for

    • BW Technologies GasAlert MicroClip XT
    • BW Technologies GasAlert Max XT-II
    • BW Technologies GasAlert Micro 5 PID
    • BW Technologies GasAlert Quattro
    • BW Technologies GasAlert Extreme GAXT-DL-2
    • BW Technologies GasAlert Extreme GAXT-DL-B-2
    • BW Equivalent part no. SR-X10-C1
    • MSA Solaris Orion Altair 4,5 (not 4X or 5X)
    • Fieldpiece SOX3
    • CityTech 4OX-2
  • Measurement Range: 0.1-20.9% Oxygen
  • Output @ 20.9% Oxygen: 80-120 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: > 24 months until 85% original Output of 20.9%


  • Dimensions (sensor): 17.4mm x 20.3mm
  • Current Consumption: 10ma peak, < 3mW average

Verify the sensor you are replacing has "AlphaSense O2-A2" printed on the side before ordering. Due to our low prices we cannot accept returns for the wrong sensor ordered.


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.

Customer Reviews

Based on 32 reviews
Donnie H
Alpha Sense 02-A2 Oxygen Sensor

Replacement for a bad 02 sensor for quattro gas alert. The Alpha Sense 02-A2 worked like it should. Back in business. Thanks Gaslab

Jennifer Condit
Great price and Fast Shipping

Sensors comes hermetically sealed with a multitude of shipping options if you call in. Simple hot swap replacement.

jonathon hornberger
No worky

Got the sensor fast and it was not expensive. The problem is that it did not work at all.

Jonathon, We ship 100s of O2-A2 sensors every month. Could the problem be the meter and not the sensor? I suggest you purchase another O2-A2. If it doesn’t work, your meter needs service, but you’ll have 2 good sensors. If the new sensor works, we’ll refund the defective one. Hope this helps.

Jurijs Kornatovskis


Allyson Tanner

Got the right part at the right price. Whoever answered my question was very helpful. Quick shipping was a bonus. Thanks!

"Swift response and shipment. The product is easy to setup and use. It is just what I was looking for."

- Shima Tomohiro

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