May 2010

All three editions of our DROPimage software include the calibration command and all of our systems ship with a Precision Combo Calibration Device (p/n 100-27-31-U). This device includes a 4mm sphere which is positioned and focused in the center of the image window. The one minute video below shows how easy it is to calibrate DROPimage Advanced. If your email does not support video playback, simply go to this page and play the first video at the top of the page: http://www.ramehart.com/goniometers/diadv.htm.

The steps involved in calibrating DROPimage as shown in the video include:

1. Placing the calibration device on the stage.

2. Centering and focusing the ball in the center of the image window.

3. Starting the calibration command using the sphere method.

4. Setting the cursor position (vertical line through the center of the circle; horizontal line under the circle).

5. And then calibrating. The results reported include the vertical and horizontal pixel dimensions in µm (microns) and the aspect ratio which should be very close to 1.0000.

For detailed step-by-step instructions, please consult the how to guides located on our support page here: http://www.ramehart.com/goniometers/support.htm

If you are using DROPimage and you require a certified calibration device, we offer p/n 100-27-31-U which is a device that has been measured and is certified with traceability to NIST and ANSI standards. All of our calibration tools can be purchased directly or on our spare parts web store www.ramehartstore.com.

Once your system is calibrated, we recommend you check your calibration on a daily basis. This will ensure that no changes have occurred that will affect the precision of your system.

Now that your instrument is calibrated, you are ready to begin taking measurements. While our tools are built to measure contact angle, surface and interfacial tension, surface energy, advancing and receding contact angle, roll-off angle, contact angle hysteresis, and even advanced rheological properties, we have a very useful command for measuring distance. Whether you wish to accurately determine the outside dimension of a needle, the thickness of your substrate, or specific drop dimensions, this command plays an important role.

The one minute video below walks through the sequences involved in measuring the diameter of a pendant drop at its widest point using the DROPimage Advanced measure distance command. If your email does not support video playback, simply go to the following page on our website and play the last video on that page: http://www.ramehart.com/goniometers/diadv.htm

Note that DROPimage Standard also has a measure distance command. It's located on the View pull-down menu. If you're interested in watching any of our additional videos which walk through various contact angle, surface tension, interfacial tension, and oscillatory measurements, you can access them here: http://www.youtube.com/ramehart.

If you are DROPimage user and have any questions regarding the calibration and measure distance commands or any other aspect of the software, don't hesitate to let us know how we can be of further assistance.