Measuring resistance from Voltage and Current signals

[David1982]

Hello,

I am using NI PCI 6040E , BNC 2090, LaBVIEW 8.5, DAQmx. I have acquired voltage and current signals for my actuator. The resistance of this actuator varies during operation. I want to graph the resistance of my actuator. I have used DAQ assistant to acquire signals. What I have done is that I have used the division function from Mathematics pallette to graph the resistance (R = V  /  I). But the graph obtained by this method is very abnormal (what I see are mostly the vertical bars). My current and voltage measurements are ok.

Thank you for the help.

[AnalogKid2DigitalMan]

Can you attach some data or screenshots of your voltage, current, and resistance data. I'm wondering if the voltage and current data are not synchronized then the resultant resistance calculation would be off. What are you measuring the resistance of- is it a pure DC component? How fast is the voltage and current changing?

-AK2DM