Measuring impedance with AT-MIO-16E??

[rqsz]

Hi to everyone,
I am starting my experience with Labview at the technical university and I have to "write" a program in Labview 6.1 that will use the NI AT-MIO-16E-10 board and will generate the signal to Analog Output, the signal will go through the chemical sensor and then through the Analog Input back into the board. And I have to measure the impedance of such a sensor. Maybe some of You had made such a thing and can help me. Right now I started learning how to work with Labview.
I would be very grateful for any response

[PauloM]

Hi,

If I understood well, you want to measure a resistive sensor using your MIO board.
You are using you AO to feed the sensor, and want to measure resistance in your AI.
The Analog Inputs of the board you mention can only measure voltage, to convet a resistance into voltage we normally use a bridge circuit - check the following link: http://zone.ni.com/devzone/conceptd.nsf/webmain/C83E9B93DE714DB08625686600704DB1 - it's about strain gauges, but the principle is the same.
For software, seach on the LabVIEW examples for DAQ voltage measurements.

Hope this gets you started,
Paulo

[rqsz]

Well, yes I want to measure impedance so I compare voltage to the current, but generally the basics are the same as with the resistance. I will try maybe someone else will say something more. but thanks anyway for Your post.

[Sean_C.]

Hello,

The best source of information when first starting out with LabVIEW would be the shipping examples. From LabVIEW, select Help >> Find Examples... From the Example Finder, Browse to: Hardware Input and Output >> DAQmx >> Analog Generation >>Voltage for Analog Ouput Examples. Browse to Input and Output >> DAQmx >> Analog Measurements for Analog Input Examples.

For Resistance Measurements, you will need some kind of External Current Excitation.

Regards,
Sean C.