# Clarification on the Seebeck Effect

Alright, I've been interested in the Seebeck effect lately, so I've been trying to learn it. From what I understand, this is measured with the Seebeck Coefficient, which gives you the $\mu\textrm{V}$ (Millionth of a volt) per $\textrm{K}$ (Kelvin). For example (according to this), if I take Molybdenum and Nickel, with 1 Kelvin of difference, I will produce 25 $\mu\textrm{V}$.

This is where I need clarification, is this per contact (of any size)?

I'd assume that size DOES matter, at which point I'd ask, what unit of surface area is this in? (ex: $\mu\textrm{V}/\textrm{K}/\text{cm}^2$)

The only reason why I'd think that it is per contact, is that I can't find any unit of surface area.

Thanks in advance for your time.

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– Qmechanic Jun 27 '13 at 14:43

## 1 Answer

The thermoelectric effect is the direct conversion of temperature differences to electric potential differences (Seebeck effect) and vice-versa (Peltier effect). When considering the electrical currents and heat fluxes involved, there is a size dependency, but such is not the case for the temperature differences and the electric potential differences involved. The proportionality factor between the temperature difference and the electric potential difference is a material dependent constant.

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Alright, so if I double the number of contact points, regardless of if I change the total surface area, I'll double the output? – John Jun 26 '13 at 3:28
Putting two thermoelectric devices (both identical and subject to the same temperature difference) in series will double the voltage generated. No difference to regular batteries really. – Johannes Jun 26 '13 at 4:45
@John - I agree with Johannes. Just to be really really clear: If you have a devices-in-parallel configuration, the voltage does not change; if you have a devices-in-series configuration the voltage does change. – Steve B Jun 27 '13 at 14:28