The “Concentration” module allow to calculate the volume of raw acid that needs to be added to the current-acid solution in order to increase its concentration to the required-acid concentration.
Below are the functions of each button and entry field in the module:

1. Return to "Home" screen
2. Access "Units" screen to change preferred units
3. Recall the saved (preferred) units
4. Save Calculation
5. e-mail calculation inputs and results
6. Share screen capture
7. Enter raw HCl acid concentration
8. Enter the current acid concentration
9. Enter the required HCl acid concentration
10. Enter water density (water used for dilution)
11. Enter the required concentrated acid volume
12. The output screen will display:
• The raw acid density at 20 ºC
• The current-acid density at 20 ºC
• The required-acid density at 20 ºC
• The Raw acid volume needed to increase the current-acid to the required-acid concentration
• The current-acid volume to be used in order to provide the required-acid volume.
13. Double tap the results window to copy results to clipboard
14. This textbook is used to display the name of the saved calculation or to type in a name to save calculation under (?)
15. Rotate pickerview to revert back to a saved calculation
16. Swipe left on the pickerview to delete the selected record
17. Double tap the pickerview to load the selected calculation. This is required when you recall the preferred units (bullet 3) and want to load back the saved caculation selected in the pickerview.

1. Complete all data entries (from step 7 to 10 above)
2. Tap anywhere on the screen to process calculation
3. Type the record name in textbox (12)
4. Press save button (4)