Expedition Navigation Software 
1 of 1- us7070
- Expert
Offline - Registered: 12/06/2017
- Posts: 260
B&G - Conflicting calibrations; Zeus vs. H5000
I ran into a problem recently where the depth indicated by instruments didn't make sense with the actual depths - it was shallower by about 2.5m than it should have been.
Figuring that the boat was setup to show depth below keel, i checked the depth offset on one of the MFD's and it read 0m. Websocket connection to the H5000 processor also showed 0m.
The boat has three Zeus chartplotters - one at each helm, and a black box below at the nav station. ultimately we found that one of the helm Zeus had an offset of 2.4m entered.
The Zesus 2 install manual says that a calibration entered in a zeus will only affect that unit, and not any units on the network. Nevertheless, the calibration did propagate to the other helm zeus.
i am not sure whether the offset affected the numbers displayed on the H5000 displays - i gather it should not have...
what is the best practice in this situation?
Zeus only stores a few calibrations - it does not store any wind calibrations. just depth, speed, water temp and mslp, i think. it gets calibrated wind numbers from the 5000
It seems like each Zeus should have it's own calibrations for those 4 numbers- it does not appear that any calibrations entered in the H5000 for those non-wind numbers affect the Zeus display.
mostly i want depth and speed to agree between the 5000, and the Zeus - water temp and MSLP i get off the 500 anyway.. Depth offset is a one-time thing.., but the speed cal gets changed fairly regularly.
If i am changing the speed cal on the H5000, it seems like i need to go do it on all the chartplotters too.
is that right?
- pivata
- Expert
Offline
- From: Sydney Australia
- Registered: 3/18/2016
- Posts: 10
Re: B&G - Conflicting calibrations; Zeus vs. H5000
Sailing on a boat with H5000 Hercules as a replacement for the H3000. The depth calibration offset was entered as 0.5 m which is the depth of the transducer from the waterline. This gave silly results such as -1.8m (ie grounded) when in fact the boat hadn't. Eventually solved by taking 4 depth measurements with a weight on a string line and measuring the wetted length, averaging and then adjusting this offset to equal the depth under the keel ie measured depth less draft.
Some weeks later by accident I discovered that there is a global depth initial value which is used for calculating depth.
This value is in the section Settings> NMEA2000 Compatibility. A value had been entered by someone (installer?) which affected the depth calibration offset value as described in the manual. So I suggest looking in this section to see if there is a value other than 0 entered for depth.
Conclusion is that for the H5000 there are 2 places where the depth calibration can be done but only 1 mentioned in the manual. This has been found to be the same for a simple Triton2 install.
If you rest you rust
- benhowett
- Expert
Offline
- Registered: 9/16/2015
- Posts: 32
Re: B&G - Conflicting calibrations; Zeus vs. H5000
It's worth noting for anyone stuck with this in the future that many of the 'smart' depth transducers can be calibrated internally, as well as most systems being able to calibrate the received depth and rebroadcast - This is why people are finding more than one calibration value. Its worth checking your sources and seeing whether your display is pulling depth from a processor, or directly from the N2K bus and trying to standardise this, and to pick a calibration point and stick with it rather than mixing and matching.