One of our current series of experiments measures heating and cooling
curves. They have an electric heater in the usual metal calorimeter block,
but with a Pasco temperature probe instead of the usual thermometer. This
sits in front of a fan to give constant convection conditions. The computer
logs temperature vs time and very beautiful curves appear... but...
Every now and then a section of the curve is displaced upwards. For a period
of about 5 minutes the temperatures recorded are about 4 degrees higher,
then they drop back down to be once again consistent with earlier
measurements. Obviously a measurement problem. Does anyone know what causes it?
Mark
Mark Sylvester
UWC of the Adriatic
34013 Duino TS
Italy
msylvest@spin.it