Examining the polarity marks of each junction (type E thermocouple wires are assumed in this
example: chromel and constantan), we see that all the “hot” junctions’ voltages aid each other, as do
all the “cold” junctions’ voltages. Like all thermocouple circuits, though, the each “cold” junction
voltage opposes each the “hot” junction voltage. The example thermopile shown in this diagram,
with four hot junctions and four cold junctions, will generate four times the potential difference that
a single type E thermocouple hot/cold junction pair would generate, assuming all the hot junctions
are at the same temperature and all the cold junctions are at the same temperature.