Underwater Sonars & Calibration (Using MaxBotix MB7092 Water Resistant Model)

[macdad-]

Good afternoon everyone,

I am using the MaxBotix MB7092 sonar:


I've been doing my homework and have been stumped on trying to get underwater ranging finding to work. I've looked at the numerous threads (& followed his video on it) that Admin & others have made yet I'm still having trouble.

I know that temperature and salinity can affect the readings and I've been actively trying to compensate for that in the code by measuring temperature from a separate sensor and multiplying the analog reading from the sonar by 4 on average (Fresh water @ 20°C) and still no luck. I've also tried compensating for it from the Serial output of the sonar to no avail.

End goal is to get it measuring the depth from the bottom of a boat to the lake/pool bed between atleast 1m upwards to 20m range (As the min & max distances of the sonar are multiplied by 4 atleast according to this blog post).

Has anyone had luck with these water resistant MaxBotix sensors underwater and if so can I see their code and hear their methods as I'm stumped. 

Fortunately, even after applying the Silicone Sealant around the transducer to seal it, it still works just fine in open air with no loss in precision.

Cheers.

[Glitchwich]

Hey Macdad, exactly the same situation here with the MB7092; silicone works in air, but no dice underwater.  I know it has been a while, but have you overcome this challenge?  How did you do it?  I think there is a lot of people interested in underwater ranging who would benefit.

[update 5/16/17]

MB7092 contains active filtering and will show last position if it cannot get 3 consecutive readings within 1 cm.  I think it may be tossing out the requested readings.  Ordered an MB7060 compact and will let everyone know how that works.

[update 5/18/17]
MB7067 (compact version with no horn) works with my test water column.