B&G and DST 800

[hornet2021]

My Airmar DST 800 is connected with a B&G Zeus3 speed is callibrated with the internal GPS so speed reading is less than ± 0.1 0.2 knots speed between 5-6 knots.
But the distance mesurements is very wrong, over 20 myls on the GPS the trip log Zeus3 is 20.3 miles but the distance from the DST 800 says 27.3 miles on the B&G Triton instruments.

How is this possible? how to callibrate

[mglonnro]

Originally Posted by hornet2021

My Airmar DST 800 is connected with a B&G Zeus3 speed is callibrated with the internal GPS so speed reading is less than ± 0.1 0.2 knots speed between 5-6 knots.
But the distance mesurements is very wrong, over 20 myls on the GPS the trip log Zeus3 is 20.3 miles but the distance from the DST 800 says 27.3 miles on the B&G Triton instruments.

How is this possible? how to callibrate

Not saying nothing is wrong there, but they are two different distance measurements that wouldn't have to be the same even when calibrated. (Though, if they are roughly the same during the whole trip, the difference shouldn't obviously be that big.)

DST log = water flowing under the boat, GPS log = land flowing under the boat.

[hornet2021]

Originally Posted by mglonnro

Not saying nothing is wrong there, but they are two different distance measurements that wouldn't have to be the same even when calibrated. (Though, if they are roughly the same during the whole trip, the difference shouldn't obviously be that big.)

DST log = water flowing under the boat, GPS log = land flowing under the boat.

I am callibrating the ST800 so the speed reading is 100% with the reading of the Triton on a lake with no current and no wind.

[mglonnro]

Originally Posted by hornet2021

I am callibrating the ST800 so the speed reading is 100% with the reading of the Triton on a lake with no current and no wind.

Interesting, indeed!

[Paul L]

Originally Posted by hornet2021

My Airmar DST 800 is connected with a B&G Zeus3 speed is callibrated with the internal GPS so speed reading is less than ± 0.1 0.2 knots speed between 5-6 knots.
But the distance mesurements is very wrong, over 20 myls on the GPS the trip log Zeus3 is 20.3 miles but the distance from the DST 800 says 27.3 miles on the B&G Triton instruments.

How is this possible? how to callibrate

Did the logs both get reset at the same time?
Was there any current?

[Dockhead]

First of all, clean the paddlewheel every day. The slightest fouling will screw up the data.



Second, calibrate it on a two-way run. Even if you think there's no wind or current, it doesn't mean there isn't one.



Third -- keep in mind that the Zeus can't calibrate at different speed points -- it only applies a single offset factor to all speeds. This sucks -- because the offset factor is actually a curve which needs at least two speed points. I think the H5000 can do this. Perhaps the new smart Airmar transducers have a way to calibrate on multiple points.


It's very good you're comparing distance, but do it on a two-way run.

[GordMay]

Greetings and welcome aboard the CF, hornet.

[hornet2021]

Originally Posted by Paul L

Did the logs both get reset at the same time?
Was there any current?

Yes the problem is on the Zeus3 log distance is correct but on the Triton display's 5 in total the reading of the distance is way off up to 30%