Load the TAPPI transparent chart software onto your computer. Purchase the software from the TAPPI organization by calling: 1-800-332-8686.
Attach a mechanical ocular adapter to the eyepiece of a 100-power magnifier microscope. Attach a digital camera able to capture photos up to 1600-by-1200 pixels per inch (PPI) to the adapter. Follow adapter instructions for connections to the microscope and the camera.
Insert the microscope slide containing the dirt specks onto the microscope stage. Adjust the light aperture and focus via TAPPI chart instructions. Take a picture of the spec with the camera to create a photomicrograph. Save the photomicrographic image as a GIF or JPEG file onto the camera's memory card.
Upload the image from the memory card onto the computer. Open the image in the TAPPI software. Follow prefabricated software instructions to analyze and process the photomicrograph to determine a size in accordance with the digital TAPPI chart.