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From 2012.igem.org

Contents 1 Dynamic Light Scattering user manual 1.1 Preperation of the DLS-machine 1.2 Preperation of the computer 1.3 Shutting off 1.4 Remember! 1.5 Note

Dynamic Light Scattering user manual

Preperation of the DLS-machine

1. If you are an experienced user of one of the DLS setups, you can use this manual as a reminder to perform your measurments on DLS-3. If you want something measured, contact Mark van Veen.
2. If the laser is note switched on. The power supply is the small black box on the left side on the bread board. Wait about five minutes for the laser to warm up.
3. Switch on the power supply of the Photo Multiplier detector. (This is the small metal box under the table with the blue cover and the note ”Thorn EMI Electron Tube” on the front panel).
4. Check if the thermostatic bath (Haake Phoenix II P2) is switched on. If not, switch it on and wait for the bath to start. Also check if the bath is circulating. If not, the text on the display next to the top button in the left says ‘start’. Press this button to start the pump. The pump will start and the text will change to ‘stop’.

Preperation of the computer

1. If the computer is not switched on yet, start it and log in.
2. If the ALV software is not started yet you should do the following:
• Start the program by clicking the shortcut “ALV5000” on the desktop.
3. If the program has started, press F7 or go to “Setup” and choose “Option Setup”.
4. Now the “Option Setup” screen will open.
5. Check if the other parameters are set right (usually they are):
1. ALV-LSE Support:
• No additional hardware is present
2. ALV-LSE:
• Measure temperature & Diode via ALV-Correlation: No
3. General:
• Setting not important
4. Detector and Detector Safety:
• Count Rate Alert at 5000.000kHz
• “Pseudocross” detection used: No
6. Click “OK” to leave the “Options Setup”screen.
7. Now click “Sample” in the menu bar and a box named “Sample Description” will appear.
8. If you want the software to correct the viscosity and the refractive index of the solvent automaticly, you should select both:
• Use table Refractive Index Information: Yes
• Correct Solvent Viscosity for Temperature: Yes
9. Check if the selected solvent in the is the right one (usually water).
10. Click “OK” to close the “Sample Description Box”
11. You can run a (short) measurement by clicking the “Play” button at the top-middle of the screen.
12. If you are satisfied with the signal etc. you can start a script to do a measurement run.
13. You simply run these scripts (or if you do not like them use it as an example to build your own.)
14. Please do not edit them, but make a copy and use that as a starting point to write your own script file.
1. To do so click “Scripts” in the menu bar and go to the script window (sometimes it appears minimized in the lower left corner of the screen) and click File-> Open.
2. Go to the SCRIPTS folder. Now you see standard scripts:
3. Standard Script: default.scp
• Does one run and saves both the raw and the fitted data / results of the fits.
4. Standard Script: titration.scp
• Does a titration run and saves both the raw and the fitted data / results of the fits.
• If you are using a titration script, you should start the titration program.
5. Open the script of your choice and click “Compile”.
• Now you can start the script by clicking “Run” in the menu bar.

The script will run automatically and will ask you all necessary parameters.

6. Standard Script: tempramp.scp
• This script will run a temperature ramp and will ask for all necessary parameters.(There is seperate manual that explains this script.)

Shutting off

Switch off the power of the Photo Multiplier detector switch off the laser and shut down the titration computer. Do not switch off the DLS-computer!!

Remember!

You are free to use these scripts as they are. You can also use them as an example to build your own. Do so by saving it (File->Save) with a new file name. Then load the saved file (File->Open) and start editing. As mentioned before, please do not edit or change the existing scripts!!

Note

This setup is not equipped with a goniometer and therefor only measures at a detection angle of 90 degrees. As this is a “home-made” setup, the ALV5000 program is not capable of reading the actual temperature; the program is however controlling the correlator (which is an ALV part). Therefor reading the actual temperature is done within the available scripts. This means that running a manual measurement (by pressing the “Play” button or pressing “F2”) is possible, but the instrument does not read the actual temperature. In such a case the program uses the previous value for temperature and viscosity to fit and calculate results. If you use the scripts, it will always measure and use actual values, So preferably use the available sripts (or you have to be sure that you know what you are doing....)