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TOF sensor: Distinguish between multiple reflective surfaces

MBaum.7
Associate III

Used sensor: VL53L1X

Application: TOF sensor is on bottom of a liquid filled container to measure the fill level. The light of the TOF-sensor is reflected on:

1) Liquid surface (water to air, oil to air)

2) Container roof surface

Is it possible to mask out one of the reflective surfaces by limit the accepted distance for the measurement (or better: time of flight) to an expected range?

E.g: The red light in the sketch will have a longer 'travel time' as the magenta light because the time to travel trough the air volume is added. If I could mask the sensor to 'see' only times below/above a given limit, I could mask out one of the reflective surfaces.

MBaum7_0-1701242349554.png

 

1 ACCEPTED SOLUTION

Accepted Solutions
Anne BIGOT
ST Employee

Hello,

Using VL53L1X it is not possible to distinguish between the two surfaces.
One option could  be to use histograms sensors like VL53L1CB or VL53L7CH or VL53L8CH.
It the condition of a VL53L1CB, the minimum distance between the two surfaces should be 80cm.

In the case of the VL53L7CH or VL53L8CH, the minimum distance between the two surfaces should be 6cm.

Regards

View solution in original post

1 REPLY 1
Anne BIGOT
ST Employee

Hello,

Using VL53L1X it is not possible to distinguish between the two surfaces.
One option could  be to use histograms sensors like VL53L1CB or VL53L7CH or VL53L8CH.
It the condition of a VL53L1CB, the minimum distance between the two surfaces should be 80cm.

In the case of the VL53L7CH or VL53L8CH, the minimum distance between the two surfaces should be 6cm.

Regards