Review of some thermal sensors for the NXT

MDP Dave Astolfo has published a review of a set of Dexter Industries Thermal Sensors and compared them to the LEGO® Education NXT Temperature Sensor.
Have a look at the according page at


Brian Davis said…
Hmm. I'd disagree with some of the points in this review (I've been working with the sensors as well, and need to get my own review out sometimes soon). The DI sensors here are analog (thermistors), which means they tend to have a non-linear response to temperature. That's OK (well known), but it means the resolution of these sensors varies across their measurement range... something that is not visible in Dave's analysis, and is important when using sensors like this. He also notes that " is also quite possible that the Dexter sensors may be able to report temperature readings tenths at a later time". That may be true - but it comes dangerously close to implying that these sensors might match the LEGO stock sensor. They can't. The LEGO stock sensor is digital within the sensor, and is therefore not limited by the on-board A-to-D encoder in the NXT, as any analog sensor would.

They *are* less expensive, and well-constructed. They potentially could be used (with longer wires) in places the LEGO sensor can not (over a meter away from the NXT). The bare thermistor version can have a rapid response in a small area. But I wouldn't imply that these sensor are at all interchangeable with the LEGO Ed version. For some things, they're "just as good" (see Dave's graph)... but for some things, they are very different.

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