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Hello. I have DAQCard-1200 and LabVIEW 5.0.1f. I should measure resistance in range 100 - 1000 kilohms. Can I do it? Please advice me. Can I use +5V from pin 49 in my DAQCard for this task?
Is circuit (see attachment) will be work? Ohm's law.
That circuit will not work as you have drawn it. It will work if you rearrange the circuit like the attached 'circuit.bmp' and use these equations.
I[R] = I[1k] = (5V-U2)/1k
R = I[R] x U2
Also note that you cannot always guarantee the supply voltage to be exactly 5V or even stay the same under load conditions. It may pay to set aside a channel to measure the 5V supply. Of course this really depends on the accuracy and repeatablility of the measurement.
Tim Streeter
Vadim Gnatkovsky wrote:
> Hello. > I have DAQCard-1200 and LabVIEW 5.0.1f. > I should measure resistance in range 100 - 1000 kilohms. > Can I do it? Please advice me. Can I use +5V from pin 49 in my DAQCard for > this task? > > Is circuit (see attachment) will be work? > Ohm's l aw. > > Thank you. > Vadim Gnatkovsky. > > Name: circuit.bmp > circuit.bmp Type: Bitmap Image (image/bmp) > Encoding: x-uuencode
