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Integrated signal from a photodiode with an NI USB-6009

I have a couple of CCD detectors which integrate the signal over time and then the measured value is recorded. This way the noise can be reduced and signal is pronounced. I wanted to do the same thing with the a photodiode (PDA 36A) from thor labs but as there is only one diode and I cannot do it via the detector itself. I was on the phone with them and they said that you could integrate the signal using the National Instrument DAQs and LabView. I was really excited to hear that but I just don't have any clue about it. I do not know where to start. 


I thought about all the professionals here and I thought maybe a kind soul could guide me a little. 


So does anyone have any ideas on how to integrate the signal (voltage) coming out of the BNC output of the photodiode over some time in order to reduce the noise and get the signal?


I would really appreciate your kind help!


If you woulike to see the VI I have created in order to measure the signal coming from the photodiode then its right here:




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Message 1 of 7

You should be able to collect a analog trace vs time and simply sum the values.  make sure you sample your PD fast enough that you do not miss any data.

It is also a good idea to sample the dark signal to remove from the measurment.

Paul Falkenstein
Coleman Technologies Inc.
CLA, CPI, AIA-Vision
Labview 4.0- 2013, RT, Vision, FPGA
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Message 2 of 7

ah any convenient way to sample the dark signal and remove from the measurement through the labview? Or, do you mean that I should measure the signal with the PD in dark and then subtract the value from all the masurements later on?


Wouldn't summing the values also have the noise included in them hence noise is also amplified if I sum the signals?

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Message 3 of 7

1.Dark signal is measured with no stimulus light and saved for later use.

2.  There is no way I know of to remove the soise from a signal unless the noise has a specific time or wavelength response.  usually you are integrating signal over time to improve count statistics.  This is for CCD I guess the PD is the same but I dont know for a fact.

Paul Falkenstein
Coleman Technologies Inc.
CLA, CPI, AIA-Vision
Labview 4.0- 2013, RT, Vision, FPGA
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Message 4 of 7

@ajeetraj Thanks for posting your code.  How did you finally tackle integrating the signal over time?  Can you post your changed VI?

Thanks in advance.

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Message 5 of 7

ajeetraj has not logged in to the Forums for 2 years.


You should probably start a new thread. Give as much information as possible about what kind of signal you want to integrate and any other relevant information.



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Message 6 of 7

Thanks Lynn.

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Message 7 of 7