How often should you change breathalyser sensors?
Modern digital breathalyzers come factory calibrated ensuring the sensor gives accurate readings. Over time these settings can be affected by exposure to alcohol and other environmental contaminants, with resulting loss of accuracy.
Breathalyzers with fixed sensors will have to be sent to a service centre for re-calibration. Breathalyzers with replaceable sensors can simply be reset to factory settings by replacing the sensor module.
How long does the breathalyser sensor keeps its accuracy for?
In normal use most sensors last 250-300 tests and can be expected to keep their settings even if not used for at least 12 months.
The following factors can decrease the above guidance.
- Exposure to extreme heat (glove box in summer)
- Exposure to extreme cold (glove box in winter)
- Exposure to high levels of alcohol in breath samples
- Failure to ventilate the sensor after use with condensation (rust)
- Exposure to tar in smokers samples
If you rely on the readings and accuracy is essential, replace the sensor every 6 months or 200 tests.
Is there any test I can do to check my breathalyser sensor is working correctly?
If your not sure how old the sensor is, or if it's been stored well, A good test is to perform a series of 3 tests on a positive breath sample over a period of 5 minutes. Any greater variation beyond +/- 10% with a good sampling technique, would indicate it's time to replace the sensor.