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DLPNIRNANOEVM: Starting parameters for device

Claire McVey
Prodigy 35 points
Part Number: DLPNIRNANOEVM

I have been trying to optimise the device settings for my application without much joy, my sample is a dried product which I am testing by via placing it on a petri dish and placing over the window (lamp turned on permanently during the analysis). I initially used the factory parameters that were in the manual, altering the width, digital resolution and scan to average. As I am not specifically looking for one peak (but differences in the whole spectra between samples) it is not conducive to determine FWHM. I tried both column and Hadamard configurations, but only seen some success with the column method as there seemed to be some interference from water (see below). I also optimised various other parameters but I observed no differences in the spectra. With the Hadamard configuration the spectra was noisy, with no defined peaks. 

Some advice on starting parameters would be great :)

column settings troubleshooting.pptx

  • 0
    TI__Mastermind 20045 points

    Hello Claire,

    Please give us a few days to look into this and get back to you with some suggestions.

    Thanks,

    Kyle

  • 0 in reply to Kyle Rakos
    TI__Mastermind 20045 points

    Hello Claire,

    I didn't mean to mark as "TI thinks resolved". We will still be looking into this.

    Thanks,

    Kyle 

  • 0 in reply to Kyle Rakos
    TI__Genius 10925 points

    Hi Claire, 

    We are still looking into this and will get back to you soon! Thanks for your patience. 

    Thanks & Regards,

    Hirak.

  • 0 in reply to Hirak Biswas
    TI__Genius 10925 points

    Hi Claire, 


    We discussed this issue, and we have some doubts regarding your setup. 

    1. You mentioned you are using DRIED product, but we see some amount of water absorption in the spectra. Could you kindly make sure that your setup/ NIRScan Nano device is not contaminated with water?

    2. Is your sample translucent? If this is the case, you need to put a reflective background behind the sample, otherwise the spectrum may not be accurate.

    3. How much consistency do you have between repeated scans of the same sample? This denotes the combined accuracy of your setup, which you need to maintain high for accurate analysis.

    Thanks & Regards,
    Hirak.

  • 0 in reply to Hirak Biswas
    Prodigy 35 points

    Hi Hirak,

    1. The sample is a totally dried product and the device has not been expose to any water so I am confused r.e. the water peak??

    2. No the sample is opaque and the petri dish is completely covered during analysis.

    3. I have attached an excel file with replicates under a set of conditions, the consistency is poor.

    Is there anyway I can check how well the instrument is running, say with a standard etc? 

    Many thanks

    Clairefactory settings 9.12.19.xlsx

  • 0 in reply to Claire McVey
    TI__Genius 10925 points

    Hi Claire, 

    Poor consistency can be usually attributed to the following points:

    1. non-uniformity in the sample. If the sample consists of coarse powder/ the composition of sample is not majorly homogeneous, scans may show inconsistency.

    2. Environmental factors: If the temperature/humidity etc changes around the scan environment, the scan results may be inconsistent. To mitigate this, taking references with regular interval is recommended. 

    3. NIRScan Nano Assembly issues: If some parts inside the NIRScan Nano is not assembled/fixed properly, minute movement of optical components can also cause inconsistencies. (This is unlikely)

    To check the device issues regarding scan data inconsistency I can pescribe the following test:
    1. Use a homogeneous solution like color water/ milk sample. 
    2. Fix the NIRScan Device near the sample. 
    3. Take multiple scan at one go WITHOUT moving the device at all. 
    4. Check the scan data consistency. 

    To further increase the consistency of scans, you can also choose to increase the number of scans to average, which will produce more consistent results. 

    Thanks & Regards,

    Hirak.

  • 0 in reply to Hirak Biswas
    Prodigy 35 points

    Hi Hirak,

    We have a lot of experience using miniaturised NIR for our particular application and haven't had any issue with non-uniformity of sample or changes in environmental conditions affecting the spectra (I believe these types of sensors should be fit for field based analysis??).

    With regard the inconsistency this is a minor issue until we can achieve a high quality spectra. 

    Is there anyone I can speak direct with about our issues?

    All the best

    Claire

  • 0 in reply to Claire McVey
    TI__Mastermind 22840 points

    Hi Claire,

    I sent request to connect so that we can have offline discussion.

    regards,

    Vivek