The voltage stays constant at 5.3 unless I turn current to voltage supplier off.

[WayneState]

I use Labview to run my PMT.  I am having trouble with the voltage.  When I turn on my current to voltage converter, the voltage reads 5.3.  However, when I turn it off, the reading displays zero.  Any ideas?  I've tried adjusting the gain, etc.  Thanks

[Ben]

double check your connections.

That is what will happen if your ground is not connected.

It would also help if you gave us hint as to what type of DAQ device you are using.

Feel free to post code if you think that can help us help YOU.

Ben

[WayneState]

I mean, my signal on Labview reads 5.3, not the voltage

[Ben]

Please provide more details.

Post a diagram of your test set-up.

Post your code.

This forum can be very helpful if you give us enough clues. Lacking that, we can only guess.

Ben

[AnalogKid2DigitalMan]

Is your PMT in the dark when you are taking your reading? It may be saturated when exposed to ambient light.

[AnalogKid2DigitalMan]

We're still in the dark on you application, but I have a hunch that if your PMT is saturated and your DAQ is set up to 5V full scale, the 5.3 reading may indicate that your DAQ input is also saturated too.

[Nick_F1]

Hi WayneState,

Thank you for posting on the National Instruments forums.

I think we need to know a little more about your system and what you are expecting to help you out.  Right now I am assuming that the 5.3 volts that you are seeing is unwanted, but what voltage are you expecting to see?  Are you expecting 0 volts like you see when you have the current to voltage converter off?  What DAQ device are you using to read the voltage?

I also wanted to make sure, when you say PMT, are you referring to a Photo Multiplier Tube?

Once we get a better idea of your situation, we can definitely help you solve the issue you are seeing.