Analog Temperature Sensor Is Accurate … sometimes

In the realm of temperature sensors available to engineers and designers, there is an endless array of choices on the market ranging from high-end precision components to low-cost, general-purpose devices. If one has a special application requiring a sensor that does not quite exist, there is no shortage of OEMs willing to custom build it.

There is one highly proprietary temperature sensor that is used but once a year that some believe to be the only choice for accurately predicting a singular change of seasons. The device of which we speak is approximately 1.5 to 2.5 feet in length and is covered with a fur-like insulator. It is mainly kept in a hole in the ground and brought out once a year for the reason of measuring the time between the end of winter and the beginning of spring,

It would be unfair to refer to this component as a mere temperature sensor as it is actually a conglomerate of numerous sensors. These include optical sensors, two to be exact, pilosensors and receptors, of course, temperature sensors, and many more that fall into the categories of neuro- and bio-sensors. A perfect example of sensor fusion if you will.


The fur-bearing sensor is put to the task of determining a seasonal change.

Once a year on February second, for approximately the past 130 years, somewhere in the wilds of Punxsutawney, Pennsylvania, this fur-insulated sensor is lured from its underground lair to record and react to environmental data relevant to the aforementioned seasonal crossover. Based on the sensor’s reaction, media folks and meteorologists alike can make an accurate prediction: there will either be an early spring or six more weeks of winter.

One might think that the furry sensor would employ its temperature sensors to make this determination, but that would be an error. The way it works is through the optical sensors, which, as mentioned earlier, there are two. Once the fur-bearing sensor is above ground, if its optical sensors detect the shadow cast by its outer chassis, it will return underground on its own power, signifying there will be six more weeks of winter. However, if the optical sensors do not detect the shadow, the spring season will be early. How early is not quite determined, which is yet another testament to the accuracy or the sensor.

One important note is that the sensor is quite delicate and great care should be exercised when handling it. If dropped, the sensor could be rendered lifeless and not good for much of anything else depending on the dietary habits of the local inhabitants. At the very least, the sensor would become quite angry,

There’s a common theory that if something is not broken, there’s no need to fix it. Therefore, we can look forward to at least another 130 years of accurate weather predictions based on our fine furry friend’s actions. By the way, if you’ve taken any of this seriously, we predict an indefinite period of insanity to follow. ~MD