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Figure 9. Coulometer Software

  1. Click Measure (Figure 9).
  2. Quickly add 5mL Then slowly add 5 mL of 2N HCl to the sample using the acid dispenser (within 10 seconds)using the connected repeater dispensette.
  3. Quickly press Measure in the sample list page of the coulometer software. If the measurement is delayed the results may underestimate the calcium carbonate percentage. A measurement screen will appear displaying real time data acquisition, the options to abort or stop the measurement, and to save/not save the results. The slope threshold is a measurement of the µg carbon with respect to time, and may be adjusted to specify the stopping point of the titration. Setting the slope threshold too low increases measurement times with the possibility of including circuit noise in the results, whereas setting the threshold too high will cause the measurement to prematurely terminate. The default slope threshold is 0.1.
  4. Once measuring is complete, click Save and record the %CaCO3, % carbon, and carbon mass in the log book. The %CaCO3 standard should give a %CaCO3 value of 100%. See the technician if this value is not acquired after running 3 standards.
  5. Wait 10-15 minutes for the system to restabilize between samples.
  6. Repeat steps 10-16 for the samples.

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