Chromatography Forum

Posted: **Fri May 30, 2008 4:17 pm**

New to the forum, I need help on creating a custom calculated field in empower. Any help will be appreciated

I like to create a custom field in empower that will calculate the % Difference (%D) in the average response factor (RF) of a reference peak for two standards following this equation

%D = [Average RF (Std1) - Average RF (Std2)] / Average RF (Std1) x 100

The sample set is as followed

3 injections of Std1 followed by 2 injections of std2.

Thanks,

TTran

Posted: **Thu Jun 05, 2008 8:07 am**

Maybe you should give us some more information about what kind of software you are using?

Ace

Posted: **Thu Jun 05, 2008 6:43 pm**

I am using Waters Empower v. 1 build 1534

Thanks,

TTran

Posted: **Thu Jun 05, 2008 7:14 pm**

Maybe you should give us some more information about what kind of software you are using?

Ace

Posted in the wrong thread...

Maybe I'm wrong, but this sounds like intersample calculations, and I'm not sure that this was possible with Empower 1.

If so, take a look at the help pages for intersample calculations, you should label your references and use this labels to get the custom fields to work.

GL

Ace

Posted: **Thu Jun 05, 2008 8:38 pm**

Thank you for replying.

My sample set is as follow:

Code: Select all

Sample Name         Injection   Label
Std1                 1             A
Std1                 2             A
Std1                 3             A
Std2                 1             B
Std2                 2             B

I created result custom fields with the following equations.

ARF_A = A..(AVE(RF))
ARF_B = B..(AVE(RF))

use the above equation, instead of calculating the Average RF, Empowers listed all 3 RF values for RF label A and 2 RF values for RF label B

Did I do something wrong?

Posted: **Sat Jun 07, 2008 5:01 am**

Thank you all, I figured it out. Forgot to add a summary calculation in sample set

Chromatography Forum

Empower custom calculated field

Empower custom calculated field

I figured it out