Which sensor is appropriate?

Hi guys, I'm looking for a sensor to detect if theres an object inside a transparent tube. Please suggest me one. I apologize if this topic has already been posted. Thanks in advance!

Is the object transparent ?
What material is the object made of ?

UKHeliBob:
Is the object transparent ?
What material is the object made of ?

Thanks for the reply. The object is a chip(not transparent), and the chip will be inserted into the transparent tube. So i want to use a sensor to detect if there is a chip inside the transparent tube.

Potato or silicon?

Seriously - explain in full; dimensions, shape, orientation, purpose.

Paul__B:
Potato or silicon?

Seriously - explain in full; dimensions, shape, orientation, purpose.

Definitely not potato, its silicon
It's an integrated chip(4mm x 2mm x 1mm), rectangle. The transparent tube is an mm wider than the chip so that the chip can be put inside the tube. The tube is long(30cm).

Obviously, a laser precisely aligned with the bore of the tube, which needs to be clamped in order to assess whether it is occupied or not.

Paul__B:
Obviously, a laser precisely aligned with the bore of the tube, which needs to be clamped in order to assess whether it is occupied or not.

Thanks for the reply. A laser sensor you mean?
If it is, how does the laser detect when the tube is empty and when it is not, because the tube is not 100% transparent, it has some scratches on its surface.

But the hole down the middle of the tube does not have scratches! :grinning:

Scratches may or may not affect the laser, depending on the frequency.

What may be more of an issue is that such laser sensors usually use IR, and many plastics are opaque to IR (depending on the frequency of the IR and the plastic material used).