Data Analysis Example

It is suggested that this section be printed before trying this example.

 The data analysis example relies on the sample data file named “break1.txt” placed into the same directory as the CanCalc Analyze Module.

1.  Click on the Analyze menu item

2.  Click on the Get Time Temperature Data selection.

3.  A new spreadsheet will be open. Find the “Read File Into the WorkSheet” button and click it. A file selection window will appear. Select Break1.txt file by double clicking to it. The data will be read into the spreadsheet. You will see three columns. The first column is time, second is retort temperature, and third is center temperature.

4. Click on the cell A1. Then highlight all the numbers in the column A by holding down the Ctlr key, at the same time hold down the Shift key and hit the Down Arrow once. You can also click on A1 and drag the cursor all the way to the end of the column.

5. With the time range highlighted, click on the Analyze menu item, and select Time range. The time data will be analyzed and if all is OK, a message to that effect will be shown. Possible errors in this step are :

   1. Non-numeric items in the range (such as a title e.g. Time)

   2. Non-increasing time numbers. You cannot have times such as 1, 2, 3, and 2 again.

8. Now, highlight the numbers in column B and click on the Analyze menu. Then click on the Retort T range. Please note that the Retort T range is not necessary (it is optional) for the analysis of data. If you do not have a retort temperature data, skip this part. The retort temperature data will be analyzed, and if all is OK, a message to this effect will be shown. OK it.

9. Finally, highlight column C, and select Analyze, then click on Center Temperature Range. The Center T and Retort T vs t window will show.

10. Using the upper left corner slider, place the green spike on the data number 199. (You will see it at the immediate right of the numbers window in the slider). Time will show 99 and Temperature will show 265.3.

11. Now click on Analyze, and select Cooling Time Start. At this point, most of the selections in the Analyze menu will become available.

12. Click on Analyze, and select Calculate fH, jH.

13. The constant retort temperature input window will open. Enter 266.

14. The program will calculate and plot log(RT-T) vs time. Also, all the possible combinations of data points will be scanned to find the best line fit (highest R square). That range will be highlighted with green in the graph.

15. It is apparent that there is a break in the line. Click on the Fit Line button (upper left). The fH, jH and R square values for the fit shown by the green line are calculated and displayed in a window. Although the fH and jH numbers are stored internally they will not be displayed anywhere else. So you might want to write them down. You can change the left and/or right border of the range to fit a line by manipulating the two sliders on top of the graph.

16. Now, click on the “up” arrow by the break label. The number 1 will appear. This means that you are now calculating parameters for break 1. Move the green range as shown by using the sliders on the upper right.

17. Click “Fit Break” button. This will fit a line to the region you selected, and display the results.

18. Click on the “Intersect” button. This will find the intersection time of the lines.

19. Now, click on the Analyze menu and select Calculate fC, jC. The program will ask the cooling water temperature. Enter 89.

20. The program will calculate and plot log(T-CT) vs time. Also, all the possible combinations of data points will be scanned to find the best line fit (highest R square). That range will be highlighted with green in the graph.

21. Click on the Fit Line button (upper left). The fC, jC and R square values for the fit shown by the green line are calculated and displayed in a window.

22. Click on Analyze and select Calculate Fo. The program will ask the z value (enter 18), and then the reference temperature (enter 250).

23. The lethal rate vs. time plot will be shown, and the area under the curve will be integrated and shown as the Fo value (7.37 mins at 250 F).

24. Click OK.

25. Click on Analyze, select Mixed Mode Parameters. The “Parameters” tab will show the values below:

26. The current values can be used to calculate temperatures. Click the “Accept and Calculate” button, with the optimization option set to “None”. Since the maximum allowed value of jH is 2.0, the program will warn of the excessive jH value, and will adjust it.

27. Click OK to start cacluations. Now click on the Graph tab to see the calculated and experimental temperatures.

28. Now, in the “Parameters” tab, click on “Minimize SS Temperatures”. The High/Low Limits tab will be enabled, and will show:

29. Adjust the jC value’s low limit to 0. Now, look at the “Values” tab:

30. Click “Accept and Calculate”. The time step will be changed as shown below:

31. The program will use simplex optimization. When convergence is reached, the “Parameters” tab will show:

32. The graph will show:

It is apparent that the calculated temperatures (the red curve) is above the experimental temperatures (the green curve). This is not acceptable. Clicking on the “Report” menu item will confirm this : look at the final calculated and experimental Fo values.

33. Therefore, adjust variables. The new High/Low limits are shown below:

34. After calculations, the new Values will be :

Note that the SS is higher in this case, but this is acceptable.

35. The new graph looks like :

The calculated curve s close to, but lower than the experimental curve.

36. The "report" shows:

A look at the calculated and experimental Fo values shows that we are close, and the experimental is higher.

This concludes the Analyze section example.