Problems With Optical Encoders: Errors & Solutions

[knight92]

Hi I was just wondering if I make a custom protractor system what errors can occur in the measurements using optical encoder ? I think if the fringes are of different sizes (human error) then it would give false data would it not ? What are some errors that can occur usually with optical encoders ?

 

[Mike_In_Plano]

There are a number of flavors of optical encoders from simple slotted disks to glass disks with photo markings on them. The latter can take you up to a resolution of about 4,000 ticks per revolution, but need to be kept clean and concentric. If the shaft wonders off from the center of the encoder, you get eccentricity in the readings and then total malfunction.

I believe DRC used to be a producer of high end optical encoders. As for the opposite extreme, the little wheels used in old fashioned computer mice are simple, but have little resolution.

Mike

 

[knight92]

Hi Mike, cheers for the reply. I don't need a high resolution but I just want to find out what can go wrong if I have a custom built protractor system. Can dust be a factor ? because mine won't be machine made ?