distance between 2 points

Hello

Looking to calculate the distance between 2 points, the disk at the end of the cylinder has a 4 inch diameter. need to be able to know the distance between the disk at the end of the stroke to the cylinder housing at all times.

what kind of sensor can actually pinpoint the 4 inch diameter disk with accuracy ?

Not enough information. Post a detailed drawing or picture of the machine.

https://www.facebook.com/photo.php?fbid=10161727180655403&set=a.10150189426200403&type=3&theater

This is the picture

IR range finder from e.g. Sharp, or ultrasonic range finders (but these could be tricky)

i ordered a sharp IR for now , looking for something that can be more pinpoint oriented.. I believe sound waves have a larger area vs light being more pinpoint no?

need to know when the piston is fully extracted and when its full inserted inside the cylinder housing.

any idea?

To determine whether the piston has reached the endpoints, many people use a microswitch:


or a flange and optointerrupter.

those require actual contact non?

The microswitches require contact, the flange and optointerrupter do not.

btourret85:
Hello

Looking to calculate the distance between 2 points, the disk at the end of the cylinder has a 4 inch diameter. need to be able to know the distance between the disk at the end of the stroke to the cylinder housing at all times.

what kind of sensor can actually pinpoint the 4 inch diameter disk with accuracy ?

With what accuracy?