Spikes Arrgghh!!!

If you've been looking at the Narberth temperature graphs you may have noticed spikes that occur at about 4pm.  Because of the location of the sensor site, that's about the time when the sun impinges on the sensor.  Due to the orientation of the street there is a brief period when the sensor gets direct sunlight, obliquely along the street.  This could be seen as a bad thing, and indeed if I were collecting scientific data concerning ambient air temperatures then it would, however, since I am not, it is an interesting indication of how much warming by direct insolation there is on a black object and how errors can occur by careless (carefree?) location of temperature sensors.  In this case it's because the sensor is encased in black heat-shrink tubing and sits on a window sill. Ideally I should protect the sensor from direct sunlight and as the summer nears I guess I will. At the moment though it's an interesting and possible usefuly artifact. 

As a challenge you could work out the location of the sensor, CSI style.  Anyone who does wins a beer.  Obvious exceptions apply.

Last changed: Feb 23 2010 at 9:57 PM