High speed and high resolution. Breakthrough ADC technology switches from 8 to 16 bits in the same oscilloscope.
It is obvious that the temperature sensors do not adequately track the actual temperatures of the plates but it is suggested that a voltage mean be taken from the heating and cooling curves. The centrally placed curve was generated from these data values and is seen to give a good straight-line graph. The reciprocal of gradient yields an output of 22.5 ± 0.5 mV per °C which is close to the manufactures' specification of 2 5mV per °C for a typical cell. (It must be noted that this conversion parameter does vary slightly with the operating temperature of the module. However, over a temperature range of 50 degrees or so, the variation will only be a few parts in a hundred.)
An ideal voltage generator should have a low internal resistance to give significant power output when a load resistor is attached to the output. The internal resistance was found to be approximately 1.8 ohms. The value given by the manufacturer was 1.5 ohms so, again, there is reasonable agreement.
Target age groups:
Ages 9 -16 (Key Stage levels 3 and 4)
The thermoelectric generator experiment is suitable for KS3 or KS4 stages as a demonstration of:
a) Energy conversion
b) Data capture
Teachers may find the following reference material useful:-
Physics Education Vol12 No6 pps 374-379