07-18-2019 11:01 AM
Hi,
I'm trying to measure the conductivity of a saline solution over a period of time. However, I'm struggling on where to even begin with this.
And advice is appreciated.
Thanks in advance,
Abby
Solved! Go to Solution.
07-18-2019 11:03 AM
What hardware are you using?
07-18-2019 11:04 AM
NI SCB-68A
07-18-2019 11:08 AM
That is a connector block (also known as a breakout board). All it does is expose different pins as screw terminals so you can easily connect wires. You will need some more hardware to be able to do anything useful with it.
07-18-2019 11:10 AM
Would that be NI PXIe-1078?
07-18-2019 11:15 AM
That is a chassis which can hold different cards. The cards themselves are what determine what kinds of signals you can send and collect.
This paper looks like a pretty good intro to measuring conductivity. It looks like you'll need some kind of a conductivity cell for your measurement.
https://www.tau.ac.il/~chemlaba/Files/Theoryconductivity.pdf
07-18-2019 11:23 AM
Would that make it NI PXIe-6363.
Thank you, I'll look at the paper
07-18-2019 11:29 AM
Yes that card has a bunch of analog inputs and a couple of analog outputs. It looks like you'll want to use the an analog output to send a voltage waveform. Then you'll want to use an analog input to measure the current, but you'll need some external circuitry to do that. A common way to convert a current to a voltage (with a known gain) is a circuit called a transimpedance amplifier.
For the software side, you can go into LabVIEW's example finder ( help >> find examples ) and type in "daqmx". This will give you many examples of different things you can do with the DAQmx drivers which control your PXIe-6363 card.