Most of our sensors last for much longer than two years. However, environmental conditions are different for our various sensors throughout the world. Exposed to certain conditions, the laser counters can become inaccurate due to the presence of debris or even insects/spiders that enter the sensor housing. This is the most common reason for a sensor to begin reporting inaccurately and can often be resolved by performing a few simple cleaning steps.
This is one of the reasons that we include two laser counters in our outdoor sensors. We compare the readings of the two channels to create a measure of sensor health called the Confidence Score, which you can see by selecting any outdoor sensor on the map (additionally, certain users will use outdoor sensors in an indoor environment, in which case, those “indoor” sensors will also include the Confidence Score as they include two laser counters). This Confidence Score is used to determine if the laser counters are reporting accurately.