## Ratio table

Ratio table contains isotope ratio and delta values calculated for each peak 
with three calculation methods (point by point PBP, linear regression slope LRS, 
peak area integration PAI) with user-selected zones of the peak.

#### Explanation of the column names

-   *Sample*: ID of the sample, helpful when several files are uploaded.
-   *Isotopes*: ID of the detected peaks (number of peaks should be same when 
several files are uploaded).
-   *BL method*: name of the selected baseline correction method.
-   *Ratio method*: name of the isotope ratio calculation method (PAI, PBP, or LRS).
-   *Zone [%]*: peak zone used for the isotope ratio calculation.
-   *Ratio P(n) (type)*: isotope ratio value of the peak. `n` is ID/index of the 
peak, peak `type` can be standard or sample.
-   *Points P(n) (type)*: number of points corresponding to the peak.
-   *Delta*: delta values calculated according to standard-sample bracketing 
method; when several standard peaks are measured, then IsoCor uses average value.

#### Explanation of the buttons located above the table

-   *Copy*: to copy the entire table
-   *Excel*: to save the table as Excel file
-   *add new zone*: select zone of the peak for isotope ratio calculation; by 
default *IsoCor* calculated isotope ratio with 100%, 95%, 90% and 80% zones to ease comparison and selection of the optimal zone\
-   *rem selected zone*: remove previously selected zone\
-   *set coef*: enter coefficient for delta scaling, find detailed explanation below

#### Explanation of the delta scaling

IsoCor gives possibility to perform delta scaling. *coef* in the formula below is a scaling coefficient. This is helpful when delta should be scaled according to the standard.

![](images/07_ratio_table_01.png)
