Protocol Procedures for OCA15EC Getting device ready to work: 1. Turn on the OCA 15 device, wait until the booting process is finished, open SCA software. 2. To set parameters for result window, movie recording, dynamic tracking go to Preferences option in Edit Preferences general preferences. Select desired option to change. In result window click display columns, highlight items to be displayed from left list and move them to right list. Check items to be exported in the window export columns, click OK when all done. Select conditions for start of movie. Select delta reference about 40-50 when optical start trigger will be used in regular contact angle measurement (dosing with electronic dosing unit). 3. Select camera speed in Edit Preferences FG setup
Regular contact angle measurement (dosing with electronic dosing unit) 4. To set the Electronic Dosing Unit to insert fully filled syringe, click on button on the top menu to open the Device Control window as shown below. Click on Maintenance button click on dispense unit icon to register ES dispense unit at position, where it is full. Prior registering dispense unit, take out syringe from dispense unit, (step 3) make velocity dialog box to max, target position 0 and click on Apply button. When done, close this window. step 1 step 2 step 3 5. In order to put syringe filled with testing liquid, press button manual mode in main menu bar- background of the screen becomes red. Manual syringe dosing buttons Up and Down are active on electronic dosing units at this mode. Piston holder position has to be adjusted by means of these buttons in order to insert syringe with piston and avoid air infusion into syringe. When syringe is in place, lock the syringe and piston holder with set screws. Click the same manual mode button again to go back to regular mode, push button to display control device window. 6. Place testing sample on the stage, adjust height of the stage so the sample appears in the lower portion of the live image window. Move the syringe (together with the electronic dosing unit) down with a help of fine adjustment screw until the tip of the needle appears in the upper portion of the live image window.
7. To dispense the testing liquid from the needle click on dispense unit icon. Select dosing volume, rate, click on dispense button. 8. Dispense the desired amount of liquid, move the stage up for the sample to pick up the drop, if the drop remains attached to needle move the stage slightly down. Adjust the lower red line in live image window as a baseline with the help of,,, buttons on your PC keypad, click profile extraction and angle computation buttons.
9. To collect the measurement results, click on File- New Window- Result Collection Window. 10. Insert drop phase, ambient phase parameters in System sub-window, needle OD (Ref. size) in M- info 11. When the drop is transferred onto the substrate, use sessile drop for contact angle measurement, place the lower line (baseline) at the bottom of the drop or between the drop and its reflection, click on profile extraction button and contact angle computation buttons. For the drop volume, base diameter, adsorption tests, make sure that the needle is in the image window and move two upper red lines are on the needle. Check if the correct needle OD is in the result window M-info as a ref. size. Click magnification (calibration button) before the calculation of results. Move same lower red line to find the baseline, and do calculations. For tracking of results over time, click button Edit Preferences general preferences.. Tracking parameters in the
12. To record a movie click on green movie button, select movie parameters by clicking. If the optical trigger is used, move the lower red line between capillary and substrate before dispensing the droplet, press on button. The software will wait till the drop crosses the red line. If the drop crossing the line doesn t start the movie, increase sensitivity by lowering delta reference in movie parameters (to about 5). If the movie starts before the drop is crossing the line, increase the delta.