As I understand it the air-water boundary is generally quite a significant density change, so I suspect you should be able to get measurements from it, but I’m not sure what kind of setup you’re proposing. There’s a minimum range for how close our Ping Sonar devices can be to their target, because the first short period of time has saturated readings due to the device “ringing” from its transmission.
It’s worth noting that the Ping2[1] has a different transducer stack, which results in a narrower beam as well as less ringing (so a shorter minimum distance).
From the technical details, our Ping Sonar has a range resolution of 0.5%, so if you configure a 2m range of distances to measure between then the resolution should be 1cm. That said, accuracy is not the same as precision, and the accuracy of the measurement is dependent on the spread of distances covered by the beam width.
As a semantic point, both the original Ping and the new Ping2 are examples of the generic “ping1d” 1-dimensional device type that uses the ping protocol for communication. ↩︎