Signal/Noise Calculation

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sivaraman_t
Posts: 4
Joined: Fri Mar 27, 2009 3:15 pm

Signal/Noise Calculation

Post by sivaraman_t »

Dear Sirs,

One of my customer is intrested in calculating Signal/Noise Ratio by the
following method. Please let me know whether we will be able to support
him through Spinchrom and if yes kindly provide the steps to achieve the
same:

1) Inject Blank first & then inject Standard.
2) Calculate W05 of peak of intrest. Take twenty times that of W05 in
Blank at the same time of Peak RT.
3) Calculate S/N thro following formula: (H/h)*2. where H is height of
peak and h is height of noise.

Kindly revert back at the earliest.

Best Regards,

T.Sivaraman.
sivaraman

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Ivan Vins
DataApex Support
DataApex Support
Posts: 183
Joined: Fri Mar 27, 2009 3:16 pm

Signal/Noise Calculation

Post by Ivan Vins »

Dear Mr. Sivamaran.

this can be easily achieved by using the User columns calculations.

1) determine the peak width of peak of interest - the W05 value is reported in results table for UNCAL type of calculation.

2) set the interval for noise determination in the blank chromatogram - use the Integration table operation Noise Evaluation (accessible from the Chromatogram/Noise&Drift menu in the Chromatogram window. The desired Noise value will be then reported in a line under the Result Table header

3) set the User Column expression (use command Add User column from the Edit menu in Chromatogram window, focus must be in the Result table). Use the [Height] from the Columns variables for peak height and enter the found noise value as a constant.

In case the noise could be determined in the same chromatogram (i.e. in a neighbouring baseline area of the peak), the Noise from the Variables in the User columns can be used for the calculation. The user columns however do not support calculations based on values from different chromatograms

Best regards

Ivan Vins

DataApex
Ivan Vinš

sivaraman_t
Posts: 4
Joined: Fri Mar 27, 2009 3:15 pm

Signal/Noise Calculation

Post by sivaraman_t »

Dear Mr.Ivan Vins,

Thank you for your support. I just sent the following mail to my
customer before 20 minutes thinking there will be some better way also
to do the same. Any way.

Quote.
Dear Sir,

I have a temporary solution for you. Kindly advice your laboratory
people to follow the following steps:

1) Inject Blank & get the noise calculated at any specific period of
time where they require.
2) Calculate the noise for the blank through right click noise calculation.
3) Now Noise of blank will be displayed in the report.
4) Inject the standard. After you get the report go to report and right
click to setup columns.
5) The formula already installed is 2*[Height]/[Noise].
6) Please insert the following formula: 2*[Height]/Value of Noise
displayed by Software for blank.

This way the problem can be sorted out. I will defenitely try my best
still to support you by a better way for getting the results.

Thanking you and assuring you the best of our services at all times,

Sincerely yours,


T.Sivaraman.
Unquote

Thank you for your support. I think in your next update you can kindly
think of this.

Best Regards,

T,Sivaraman.
sivaraman

sivaraman_t
Posts: 4
Joined: Fri Mar 27, 2009 3:15 pm

Signal/Noise Calculation

Post by sivaraman_t »

Dear Sir,

The Signal to Noise ration problem is shorted out but there is small problem which we have started facing.

Many times the run starts from 625 volts can you please advise. This problem occurring intermittently. Please kindly mentioned to solve this problem.

With Best Regards,
T. Sivaraman
Spinco Biotech Pvt. Ltd
Baroda
sivaraman

User avatar
Ivan Vins
DataApex Support
DataApex Support
Posts: 183
Joined: Fri Mar 27, 2009 3:16 pm

Signal/Noise Calculation

Post by Ivan Vins »

Dear Mr. Sivamaran,

Similar bug occured in certain Clarity 2.3 versions, the bipolar settings of the detector were errorneously identified as unipolar thus the baseline was shifted by a half of the used range and the signal height was reduced to half. Upgrade to current version available from our web pages should solve this problem.

Best regards

Ivan Vins

DataApex

Ivan Vinš

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