Range issues with Multifunction DAQ

[shareef]

For my academic project, I need to acquire leakage current of high voltage insulator . We have PCI multifunction DAQ in out laboratory. The Current range of DAQ device is 20mA. But we need to acquire current with a value approximately in the range of 150mA to 225mA. So we could not proceed further acquisition, and also running out of time. How could we possibly acquire the current with the existing DAQ card.? Is it possible to use any scaling resistors, or any other possibility in acquiring the current with the same DAQ card? Is ther any other instruments with higher rating? Please help me sort out this issue...

Thanks in advance...

[kekin]

The simplest thing you can do is to use accurate 33ohm resistor in series & measure the voltage across it.

But I would recommend to use op-amp based "I to V converter circuits"  & then measure the amplified voltage for better resolution.

[shareef]

Thanks for the reply. I have succeeded in acquiring the signal after converting it to voltage by placing 22ohm resistor. Its working fine.

Now I need to develop the acquisition process into a stand alone module that can be used anywhere. what are the procedures to be followed for the process? what are the requisities.? Currently we have LabVIEW 2008 licensed version and LabVIEW 2009 evaluation version.

Could u pls make me clear about the development of stand alone module, so that I could use it for my academic project - phase I?

Thanks in advance.