Oxygen Sensor
Expected Life, Storage Life & Warranty

Expected Life: In theory, sensor life is limited by the amount of anode material and signal output. A higher signal output yields a shorter life because the anode is being consumed at a faster rate. In reality, the Expected Life specification considers the signal output range, for example 7-13 mV.

In general, sensor life is inversely proportional to changes from the specified parameters for oxygen concentration (air 20.9%) and pressure (1 atm), and, exponential (2.5% per °C) for temperature changes from (25°C/77°F).

For example, a medical oxygen sensor (overall life varies refer to individual specifications) configured for an overall life of approximately 68 months (1,032,000 % oxygen hours) based on the above parameters of oxygen concentration (air 20.9%), temperature (25°C/77°F) and pressure (1 atm) would reflect the following published specifications and margin of error for the overall life of 68 months:

- Expected Service Life of 60 months (915,420 oxygen % hours)
- Recommended Storage Life period of <6 months (91,542 % oxygen hours)
- Marginal of error of 2 months

Storage Life: The recommended storage life period should not be considered a perishable shelf life. Operating at the specified parameters of oxygen concentration (air 20.9%), temperature (25°C/77°F) and pressure (1 atm), the sensor will operate for approximately 68 months whether in storage or in use. The purpose of the Recommended Storage Life period is to ensure the user derives the Expected Life of and does not lose the benefit of the warranty.

Extending Life: In general, sensor life is inversely proportional to changes from the specified oxygen concentration and pressure parameters, and, by 2.5% per °C of changes in temperature whether in service or storage. With the exception of the following recommendations reducing any of these parameters will extend the life of a sensor to some degree.

Recommendations: Do not store, operate or freeze any sensor below the lower temperature range specified. Do not deprive Percentage Range sensors of oxygen completely below 0.1% or 1000 PPM for an prolonged period of time as it will damage the sensor. Conversely, do not expose trace PPM sensors to air except to calibrate and store in the lowest oxygen concentration possible. Do not expose PPB sensors to air or attempt to calibrate with air (use a certified span gas below 100 PPM).

Warranty: The medical sensor in the above example carries an 18 month (274,626 % oxygen hours) warranty (12 month industrial) period is based on:

- Expected Life of 60 months (915,420 % oxygen hours) as described above
- Conservative assessment of the application, an average oxygen concentration of 60-70%
- Marginal of error of 2 months

The warranty period begins with the date of shipment from Analytical Industries Inc. and is limited to the first customer who submits a claim for a given serial number. Under no circumstances will the warranty extend to more than one customer or beyond the warranty period.

The warranty does not cover normal wear and tear; corrosion; damage while in transit; damage resulting from misuse or abuse (e.g. exposing the sensor to 100% oxygen for prolonged periods of time); lack of proper maintenance; unauthorized repair or modification of the analyzer; fire; flood; explosion or other failure to follow the Owner’s Manual.