Electrochemical sensors are effective and offer very good performance for monitoring a wide range of gases. Their lifespan depends on the type of gas and some other factors.


Most toxic gases and oxygen are detectable with electrochemical sensors. When sampled gas passes over the sensor an electrode converts a reaction of the gas being sampled into a measurable signal to calculate the concentration of the gas in the sampled environment. Overall, they are effective and offer very good performance for monitoring a wide range of gases including oxygen, carbon monoxide, hydrogen sulfide, sulfur dioxide, nitrogen dioxide, chlorine, ozone, and many others. However, there are a few factors to be aware of that can affect the lifespan of electrochemical sensors.

  • Repetitive and extreme changes in temperature can lead to the evaporation of the electrolyte and result in sensor drift and a slower response.
  • Operation in very low temperature environments can impede the sensitivity of the sensor and slow its the response to the target gas.
  • Continuous operation in low relative humidity environments can dry out the electrolyte and high moisture environments can cause the electrolyte to absorb the moisture, causing dilution and inaccurate measurements. The ideal environmental state for operation for electrochemical sensors is 20 OC / 68 OF and 60% RH.
  • With some target gases, like oxygen, continuous exposure to high concentrations of sulphide compounds like hydrogen sulphide can poison the sensor. Similarly, sudden, high concentrations of the target gas, like ammonia, can render the sensor useless.
  • If the gas detector is exposed to extreme vibrations or mechanical shocks, it is possible that the welded points that hold the electrodes and pins together could break or fracture, causing the sensor to stop working. This however is not a common occurrence. Electrochemical sensors are commonly made of high-quality components and are well-constructed.

Regular maintenance along with monthly bump tests and calibrations as recommended by the manufacturer (and applicable regulations) will help keep you informed about the operation of your gas detector. At any time, if you suspect something may be affecting its performance, you need to test the unit with a bump test to make sure the sensor is capable of measuring gas and if that fails, do a full calibration. If the calibration fails, you need to replace the sensor.