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Making Leaking O2 Sensors a Thing of the Past


In the same way that battery leakage damages electronic goods, electrolyte leakage from O2 sensors causes damage to host instruments, limiting their life and tarnishing the reputations of instrument manufacturers.

At Alphasense we believe instrument manufacturers and users deserve better and for that reason, we are proud to present our new improved O2-A2 and O2-A3 sensors – now guaranteed 100% leak free.


Click to download infosheet

Lead-based electrochemical O2 sensors have long been the go-to sensor for OEMs seeking accuracy and fast response in a cost-effectiveness package.

The major drawback of this type of O2 sensor however is that variation in operating conditions and product quality in the case of some manufacturers can render them prone to electrolyte leakage.




Containment is Key

Prevention of leakage may sound like an obvious solution but the drive for lower-cost O2 sensors has had a direct impact on the material selection and build quality some manufacturers employ, rendering many designs incapable of withstanding the internal pressures generated.

At Alphasense we believe electrolyte containment is the key to long-term sensor performance and protecting our customer’s valuable devices.



Whilst other manufacturers see leakage in O2 sensors as an inevitability, incorporating features such as vents that allow the sensor to relieve pressure, we believe in better, and for us that is a sensor that demonstrates zero leakage, even under the harshest of storage, transportation or operating conditions.

This new iteration of these best-selling sensors incorporates a number of innovations off the back of a root and branch design evaluation and rigorous testing programme. The result is our best-performing O2 sensor yet, now proudly backed by our 100% leak-free guarantee.



Confidence in performance

When tested alongside O2 sensors from other mainstream manufacturers, Alphasense leak free O2 sensors prove at least 3.5 times less vulnerable to atmospheric factors than their nearest competitors and are resistant to leakage for up to 10 x longer than other brands.



Further to this, when tested to destruction, 75% of the closest competitors’ sensors had leaked before the first Alphasense sensor showed any signs of leakage. Even when the last competitor sensor finally failed, 85% of Alphasense sensors were still leak-free.

To determine the anticipated lifetime of a sensor, we use accelerated life testing, a process that involves exposing the sensor to high temperature and humidity for a prolonged period whilst in operation. This process, perfected during our 25 years of O2 sensor manufacturing, simulates the very conditions which cause sensor leakages, with each day under test representing months of operation under typical ambient conditions.

These results underline the superiority of the new and improved Alphasense O2-A2 & O2-A3 sensors and demonstrate why they should be the number 1 choice for manufacturers who value the integrity of their instruments and reputations. 

Buy Cheap, Buy Twice

Whilst low-cost, budget or cheap O2 sensors may present a saving on instrument BOM cost, often single digits in $ value, the cost of leaking or failing sensors can be enormous, both directly to manufacturers and end users.

It’s difficult to quantify the financial impact of sensor leakage on OEMs or end users but the cost of a replacement sensor is typically dwarfed by the associated costs of failed calibrations, fault-finding, maintenance, warranty claims or in the extreme, expensive instrument write-offs, working days lost and projects delayed.



No leaks, no waste

Less leaking O2 sensors means fewer failures and fewer damaged instruments. That means less scrap and fewer devices being condemned to waste.

Whilst some manufacturers focus on producing high volumes of low-quality sensors, Alphasense’s goal is to create sensors that set our customer’s instruments apart from the competition through their performance.

As a business that manufactures and sells sensors, you may wonder why we’ve worked so hard to produce a sensor that fails less and lasts longer. Our response is simple – because we want to ensure Alphasense sensors remain the best.



With Alphasense O2 sensors outliving competitor sensors by at least 3 times under test conditions, the reduction in waste achieved in using Alphasense sensors is significant.


– 2 year warranty
– High-performance leak-free O2 Sensor
– Less than 1% change in output over 3 months
– T90 of less than 15 seconds
– < 0.7% Humidity affect
– < 0.1% CO2 Sensitivity
– Up to 99% humidity resistance


Download datasheet


– 3 year warranty
– High-performance leak-free O2 Sensor
– Less than 2% change in output over 3 months
– T90 of less than 15 seconds
– < 0.7% Humidity affect
– < 0.1% CO2 Sensitivity
– Up to 99% humidity resistance


Download datasheet

Moving with the times

If you are already buying the O2-A2 or O2-A3 you will soon see the benefit of the latest iteration which has been in production since mid-April. The latest generation product can be differentiated from the old since the latest version features ‘patent pending’ on the label.

With no change to part numbers or specs all existing customers have to do is enjoy the benefits

For customers who are looking to develop a new instrument or who would be interested in advancing their instruments by migrating to Alphasense sensors we will be delighted to support you on the journey.



We’re excited to bring this innovation to market for the benefit of our customers, currently more than 2000 organisations in over 180 countries

If you are looking to develop a new instrument or would be interested in advancing your instruments by integrating Alphasense leak free O2 sensors, we will be delighted to support you on the journey.

Our experienced inside sales team, factory based technical support and regional sales representatives are on hand to assist customers old and new.

 If you would like to find out more about Alphasense leak free O2 sensors or any of our other products please don’t hesitate to get in touch.