AC resistivity measurement with MyDAQ on TEC

Hello,
I would like to ask for advice: we would like to measure resisitivity of Peltier-elements. If we use DC method, because of the Seebeck-voltage of the element, we do not get the real resistivity value. The common method to use AC measurement in case of such devices. I would like to know, if it is possible to use a MyDAQ device for this task? As a first approach we do not need the best accuracy, this would be more as a "broken-element" test (there is usually a significant shift away from the nominal AC resistivity value stated by the manufacturer).
What would be the easiest way to carry out a simple measurement? What about if I use one analogue output of the MyDAQ lets say with 1kHz, and I drive the Peltier-element with this voltage AC source? And I connect a known resistor in series, and I measure the AC voltage drop on this. From this data, I could calculate the current, and the AC resistance of the Peltier-element? Of course I have to choose a resistor so the MyDAQ can drive the network.
what is your opinion, where to start?
Thanks!
Solved!
Go to Solution.

Hello, thanks for the reply!
Actually I am just going to replace 60 Peltier elements in a "home-made" 15 years old heat exchanger (I expect to find some mice too ). This assembly has dropped performance (heat transfer power) and also I know that, a few years ago after a malfunction with the hot side cooling fans, this device was running for a certain time without forced cooling. What is quite bad in case of Peltier-elements. I have already bought 65 brand new Peltier-modules and after I get some heat conducting paste, I will replace them. And I will have 60 pieces of old Peltier modules, to play with them
Since I have this NI MyDAQ, I thought it would be fun (and would give also valuable information) to try to measure the old elements' AC resistivity. Since this task is not like I should do often, so for first, I would not like to go for more pro solutions, I will try the MyDAQ first.
 I expect that some of the modules got structural degradation during the heat shock, and this may be measurable in a shifted AC resistance.
I would do the measurement with zero applied DC voltage. These modules are Melcor PT3-12-30L (discontinued product), the nominal module resistance is about 5 Ohm.
EDIT: and would you recommend a certain circuit to try? Shell I use a known resistor for current measurement via measuring the voltage on it? Or I could use a known AC current to drive the Peltier, and I would measure the resulted AC Voltage on it?

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