Hello,

I built thermopile (Al/polysilicon pairs) with one junction on a silicon
oxide/nitride membrane (for good thermal isolation) with which I want to
measure the temperature. Usually the output voltage should be zero. I
dropped a room temperature water droplet on the membrane and the output
voltage went down abruptly and went back to zero slowly. But I expected
the output voltage will not change because the droplet has the same
temperature with ambient. Did anyone meet this kind of problem before? Is
it because the temperature fluctuation in the droplet? Is it because the
deformation in membrane will change the output voltage in the bi-material
junction? How can I avoid this systematic error?

Thank you in advance.

Li