You couldn't afford the Sperry unit anyway.......it is very expensive. From your comment, I assume you don't have the rest of the
system (processor and display) How are you going to use it? I will find an impeller measure it and get back to you.
Steve

"Moonshadow" wrote in message ...
We will be using them to measure water currents past our jetty due to passing shipping.

Steve Lusardi wrote:
I am very curious why you ask. This system has been out of production for a long time now. I too am a fond user, so I am also
concerned about the availability of spares to keep it running.

They are an old design, but we've just bought two so they are still available.

I hope you realize that it is designed to produce the same pulse train rate of the conventional impeller, as the electronics
beyond the speed box are interchangeable. So it shouldn't be rocket science, once the impeller pitch is measured.

We don't have a conventional impeller to measure, and I can't find info regarding its ppnm rate anywhere either.

Sperry Marine make a much more sophisticated version for ships. That system measures flow in both the x and y direction and can
have multiple sensors on the hull. Its purpose is primarily used to measure water currents when inshore.

Hmmm. Pity I didn't know about that earlier. Too late - I must use what I've got.

Thanks for your comments.

Thanks Steve.

I will design and build a PIC-based interface which will deliver
NMEA-formatted proprietary sentences containing the current rates from
the two Sonic Speed systems. Others will organise for these data to get
to our servers via various boxes of tricks and WiFi. The data from these
will be logged, and probably be made available in real time via the
Internet.

Steve Lusardi wrote:
You couldn't afford the Sperry unit anyway.......it is very expensive.
From your comment, I assume you don't have the rest of the system
(processor and display) How are you going to use it? I will find an
impeller measure it and get back to you.
Steve