From Physics 111-Lab Wiki

All pages in this lab

I. Nuclear Magnetic Resonance

VIII. NMR Scope Program

IX. Pulsed NMR

X. Pulsed NMR Equipment

XI. Pulsed NMR Setup

XII. Pulsed NMR Appendices

---

CW Appendix IV

How to transfer data from the scope to the computer.

Setup:

First we need to make a connection between the computer and the oscilloscope. To do that, locate the aluminum box labeled Computer Interface Unit. Connect the X input (X/Trig CW) with the knob on the Hmod corresponding to the sign "to oscilloscope". Connect the Y input (Y In) with the output of PRE-AMP. The other port of the interface unit should have a 50-ohm termination. Don't forget to turn on the Computer Interface Unit.

Now we are ready to use the computer to transfer the data.

NMR Scope Program

The program we are going to use to transfer the data is called NMR Scope. To get familiar with the program you might want to follow the following simple exercise.

On the desktop you will find an icon NMR Scope. Double click on that icon to open up the program. You will see the following window:

1. First select the type of experiment you are doing. There are two options: Pulsed NMR Rising Edge Triggering and CW NMR Falling Edge Triggering
2. At the bottom left corner you will see three buttons: Display TY, Display XY, and Display Strip Chart. The latter one will be used later in the experiment. For now, press either Display TY or Display XY button.
3. To see the signal press the TY Mode or the XY Mode, depending on the previous choice you have made. You should now see a signal in the upper right chart. This is what it might look like:

TY Mode

XY Mode

4. To stop the signal, press Quit TY, or Quit XY signal accordingly.

5. To save the data, press Save Current TY/XY Traces. Save the data as a .dat file format.

6. To clear the graph, press Clear TY/XY Traces.

Note: you can actually copy the graph and print it separately. Right click anywhere on the graph and press Copy Data. This temporary stores the image on the computer and you can paste it in most programs such as word or excel.

Averaging the Data:

We can also "average out" the signal to get a smother line. The program takes multiple samples over time and takes the average. You can average the data in wither mode: TY or XY. After choosing the mode, you might want to go over the following steps:

1. Press TY/XY Average. The window comes up asking if you want to "AutoSave the data." If you wish to do so, press yes and it will prompt you to save it. Otherwise, press no. In either case, you will get a window, asking to "Chose Acquisition Points." Just press ok. In the middle to the left of the program window you can set either the acquisition time or acquisition points. By default they are set to maximum.
2. Now, press Start TY/XY Average. The top right graph is the same as one before. The bottom right graph is the average graph. You might see similar graphs to the ones bellow:

TY Mode

XY Mode

3. To stop the signal, press Quit TY/XY Average.

4. To save the data press Save Averaged TY/XY Data.

5. To clear the graphs press Clear TY/XY Traces.

Strip Chart Recording Function (used in the later part of the NMR experiment)

Instead of using the actual Strip Chart Recorder, we can use the NMR Scope program to accomplish the same results. Once all the equipment has been set up properly, the use of the program is simple.

1. Set up the equipment as instructed in the section "Taking Data," part E.
2. Open the NMR Scope program.
3. Press the button Display Strip Chart. You will see that you are only given one graph space in the top right corner.
4. To start taking the data, press Start Chart. You will see something similar to the following graph:
   

   
5. To stop the signal press Stop Chart
6. To save the data press Save Strip Chart
7. To clear the data press Clear Strip Chart

This concludes the overview of the program. If you have any more questions, you can ask one of the staff members for help.