Is there any sensor for measuring smallest distance

Hello,

Is there any sensor for measuring smallest distance?

I need measure distance example: 8.25cm

I found sensor VL53L0X but it measures 82mm..

Is any solution for that?

Best wishes,
Veltix

Is there any sensor for measuring smallest distance?

As far as I know the sensor for the smallest distance is a raster tunnel microscope.

I need measure distance example: 8.25cm

I found sensor VL53L0X but it measures 82mm..

Does that mean you need sub-millimeter accuracy? I guess payable time-of-flight sensor won't match this. Please specify in detail what kind of distance you're trying to measure. What materials are used in the two objects? How much space do you have for the sensor? Tell us as much as possible.

pylon:
Does that mean you need sub-millimeter accuracy? I guess payable time-of-flight sensor won't match this. Please specify in detail what kind of distance you're trying to measure. What materials are used in the two objects? How much space do you have for the sensor? Tell us as much as possible.

Yes I need sub-millimeter accuracy. I have display in pcb and I must measure all corners to know they are not skewed +/-0.5mm max.

So I thinked if 4 sensor put on top and pointing to all corners, then I can get all corners height from pcb to top of display.

If 4 sensors are top, you fix height from pcb to sensor and then you can put pcb with display under sensor and get exact height..

I dont know how to explain.. But in my head have this idea and I need to know which sensor is really good and have sub-millimeter accuracy.

I have image, maybe you can understand me.

Thinked use leds also in corners of project so if red light turns on then it is lower than 7.7mm and other corner must be higher than 8.7mm

Contact or non-contact?

Use the part that protrudes out the right (right-hand) end...

You are definitely trying to make this more complicated than necessary. Make a go/no-go gauge out of something, a piece of aluminum or similar. Make it "L" shaped with the inside length of the "L" the exact dimension you want. Place it over the IC or whatever it is that has the limitation. IF the end of the "L" just touches the board your height is perfect.

Have made dozens of such gauges for the assembly people.

Paul

I thinked create workbench for measuring this.

So if i have fixed height on top 4 sensors, from bottom plate to sensor is 200mm, so if i put my pcb with display into plate hole it can measure all 4 corners heights from pcb to top of display.

Workbench what i created and where is sensors what can measure distance with sub-millimeter accuracy:

Calculation how it calculates it:
Fixed height from all sensors to plate is 200mm

So i have to divide from fixed height to get all corners heights with sub-millimeter accuracy.

Pcb to top of display height 8.2mm +/- 0.5mm

Corner 1 height 191.8mm = 8.20mm
Corner 2 height 191.8mm = 8.20mm
Corner 3 height 191.2mm = 8.80mm
Corner 4 height 192.4mm = 7.60mm

Corner 1 and 2 are parallel corners.
Corner 3 and 4 are parallel corners.

So 3 and 4 corner is slanted and product needs to be fixed.

I downloaded from google display image and show corner numbers:

Now question what sensor I can add height from 200mm and get sub-millimeter accuracy height from pcb to top of display?

I dont need hand tool because there is smd components and copper tracks and older people doesnt get know how to use and to get exact height, even if they try 3 times.. I've used digital sub-millimeter hand tool, but all people get difference heights and too many products and hand tool takes too much time...

Since the actual measured distance is not important, only that it's a known distance, possibly a reflector system could work. Position a laser to bounce off the board and impinge on the receiver *only *when the board is correctly in position. Above or below this distance the receiver sees no light and so is off. Do this four times.

distance check.png

Fiducials + optical flow sensor.

dougp:
Since the actual measured distance is not important, only that it's a known distance, possibly a reflector system could work. Position a laser to bounce off the board and impinge on the receiver *only * when the board is correctly in position. Above or below this distance the receiver sees no light and so is off. Do this four times.

distance check.png

With reflective sensor I have possible get distance between pcb to top of lcd? 0.1mm precision?
I thinked this is best way to get know height.

Or if there really have no any sensor what cand measure it, maybe is possible to do it manual way like hand tools, but use my workpench and get 0.1mm precision measurement?

If you didnt understand me, I can draw what I meant.