position sensor

I am looking for a sensor which have to sense a moving object from it's reference point. The accuracy required is 0.1 mm. The laser sensors are working fine but are expensive. I am looking for cost effective solution. The moving object can be a metal or non metal of any shape.Can anyone help with informations and ideas?

Talk to your Keyence guys. My guy demo'd a new laser sensor they now have that is a lot less expensive and if I remember right, the accuracy is right in your range. Unfortunately I think laser is the only reliable method at the moment.

Steve