2021-04-01 04:53 PM
Hi, We have been testing the VL53L1X for a while. The primary intend is to measure liquid level. Liquid can be water, coffee, windshield washer fluid, etc. We are seeing some issues that we cannot seem to figure out. Hoping for any insights.
Premise.
Concerns.
2021-04-12 02:47 AM
Hi ,
Liquid level measurment is tricky one because photons are travelling through Air and Water. As a result, light path is being impacted because of their different refractive indices. In other words, there is a possibility of part of the signal reflected from the surface, partly travelled through water and returned from the container’s base and partly multi bounce from the water itself. Thus, the final ranging distance is impacted with respect to accuracy.
So there is a possiblity that when the liquid level is less then half sensor may give over ranging as signal may reflect from suface as well. if liquid level is more then half then may get under ranging because partly signals absorbed by water.
So you could do post offset correction for over ranging part and for underranging (refractive index of liquid) + offset correction to get good accuracy.
When I say offset correction its not offset calibration , its post offset correction of recived ranging measurment.
Regards,
Aditya
2021-04-22 11:14 PM
Hi @ACher.4 ,
any feedback for Aditya answer?
-Eleon
2021-04-23 09:40 AM
Hi Aditya, Eleon,
Sorry I could not respond earlier due to other commitments. We did play around with the timing budget and intermeasurement period (we only need very slow rates) and saw better results. Tests are still running, however, we got pushed away from this sensor for a while, but we plan on getting back to this shortly. I will update you with my findings thereafter. Thank you for the follow up.
A. Cherian