Time page

Plot absorbance, transmittance, or concentration versus time for solutions undergoing a reaction.

Note

• Before analyzing the time, you must go to the Analyze Solution page, record a solution run, and specify its analysis wavelength.

• If analyzing concentration versus time, the measurement will only be meaningful if the absorbance versus concentration relationship is established in an experiment on the Concentration page, OR if the slope and intercept are entered manually.

1. Quick Calcs

   Click to apply a calculation to the y-axis measurement. Possible calculations include natural log (ln y) and inverse (1/y).

2. Data run selector

   A new data run appears every time data recording begins. Click to select the data run you want to display. To rename a run, click on the run and click . To delete a run, click on the run and click .

3. y-axis Measurement

   Click the displayed measurement to switch between viewing Absorbance, Transmittance, and Concentration on the y-axis.

4. Monitor tool

   This tool displays the live time and y-axis measurements in a digits display during data collection. Click to show or hide the tool.

5. Live Scan Display

   The Live Scan Display shows the Absorbance (or Transmittance) versus Wavelength graph for the sample currently being monitored. It also shows the wavelength being analyzed. Click to show or hide the display.

6. Comparison Mode

   Click to show all runs on the graph simultaneously. Click again to only show one run.

7. Selection tool

   Use this tool to highlight a group of data point to analyze, such as when performing a linear fit. Click to activate the tool then click and drag the handles on the selection box to select the data you want to analyze. Additionally, you can use this tool to zoom in on a selection of data by clicking Scale to fit after selecting the data.

8. Linear Fit tool

   Click to add a best fit line to the data. This will also display the slope (m) and y-intercept (b) of the line. The correlation coefficient (r) indicates how well the line fits the data, with 1.000 being a perfect fit.

9. Annotation tool

   Click to add a note in the graph. The tool can be attached to a data point by dragging the tool to the point. Click the annotation box to enter text.

10. Coordinates tool

    Click to add the tool to the graph. Drag the tool to a data point to view the coordinates of that point.

11. Scale to fit

    Click to automatically scale the axes so that all data is visible in the graph.

    Tip

    You can also scale the graph manually by clicking and dragging the axes or plot area.

12. Active Solution

    This field displays a list of data runs that were recorded in the Analyze Solution page. Click to select the data run (solution) you want to analyze.

13. Record

    Click to begin data recording. Click Stop to end data recording and keep the displayed data.

14. Absorbance vs. Concentration

    Contains the slope and y-intercept values that relate the absorbance to the concentration of the sample. These constants are entered automatically when a linear fit is performed on the Concentration page. They can also be entered manually by clicking each field.

15. Bandwidth

    Bandwidth specifies the range of wavelength that will be measured. It is equal to the number of pixels on either side of the pixel specified by the wavelength parameter. Therefore, the total number of pixels that will contribute to a measurement equals (Bandwidth × 2) + 1.

16. Sample rate

    The number of measurements taken per unit of time. Click + to increase and - to decrease the sample rate.

17. Fluorescence Tabs (Wireless Spectrometer only)

    The Wireless Spectrometer contains a 405 nm and 500 nm LED for use in fluorescence experiments. Use this feature to explore the excitation of substances at two different wavelengths. Click the tab to turn on the LED of the specified wavelength.