| Acidification of Milk | Note: This is a long experiment so ensure that the USB cable is connected to the einstein™ LabMate™ for the duration of the experiment, or USB cable is connected to a charging cable. 1.
Launch MiLAB (
2.
Connect the pH electrode and the Temperature Sensor to ports of the einstein™ Tablet or einstein™ LabMate. Assemble the equipment as illustrated in Figure 1. In the Current Setup Summary window choose Full Setup and use the table below to set up the experiment. Make sure that only the pH Sensor and Temperature Sensor are selected under Measurements.
3. 4.
).
Current Setup Summary Program the sensors to log data according to the following setup: pH Rate:
Every 1 min
Duration:
2000 sec
Temperature (-40°C to 140°C) Rate:
Every 1 min
Duration:
2000 sec
Procedure 1. 2. 3.
Warm 750 ml of pasteurized milk and bring it to room temperature. Pour the milk into the thermos. Insert a pH electrode in the milk and cover the thermos gently to prevent any damage to the pH cable.
4.
Tap Run (
5.
After 30 hours of incubation, you can stop data logging by Tapping Stop (
6.
Save your data by tapping Save (
) to begin recording data. ).
).
Data Analysis 1. 2. 3.
For more information on working with graphs see: Working with Graphs in MiLAB Use the cursors to mark the start and end of the experiment. Determine the extent of change in pH measured in the process. Calculate the extent of change in pH obtained in the process. Use the cursors to mark the start and end of the experiment. Apply a linear fit to the difference graph: a. Use the cursors to mark the start and end of the experiment. b. Select Linear fit. The fit equation will be displayed below the x-axis. c. The slope of the fit line is the rate of pH change.
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