Hi,
any suggestions for a sensor for measuring distance to a slow moving object inside a tube?
specs:
Tube inside diameter: 10 mm
Size of object to measure distance to: 9 mm diameter
Distance to object: 10 - 30 cm
Accuracy needed: 5 mm
thanks!
Tube and Object are going to need to be detailed.
For example, a black marble in a transparent hose: easier.
A transparent marble in a transparent hose: a little harder.
A black marble in a black hose: a lot harder
A particular black marble in a black hose filled with other black marbles: harder yet.
A black camera in a 30 cm blind borehole drilled into bedrock on the ocean floor: hard-hard.
Do you have access to the ends of the tube?
Access to the outer walls of the tube?
Describe the object.
Describe the medium (or lack) otherwise filling the tube.
An ultrasonic distance sensor would probably work to measure the distance from one end of the tube, but the accuracy would be around 1 cm. You would need one with a single transducer that both sends and receives.
For the resolution you are looking at, a VCEL sensor or RADAR sensor maybe best. But that 10mm tube diameter is certainly a challenge; plus as it was mentioned previously the material of the tube and the ball will play a large role. Anothe possibility to consider is some sort of electrical or magnetic sensor along the tube (on the outside) that senses as the ball (presumably of some conductive material) travels along the tube.