I looked into the Bohiken barograph a few years ago
it seems to have only one calibration factor - a fixed offset that appears to include both the elevation offset and any instrument error.
it does seem to automatically do the temperature correction
the Aquatech unit can be calibrated at something like 10 values within the normal range of MSLP variation - this is better, as the instrument error is not constant across the range of pressures we might encounter. It also has an elevation offset. I think the Aquatech has no capacity for output to an instrument system or PC
It appears that the mintaka has two calibrations - an elevation offset, and a single instrument error correction.
i think what i really want is something with the high quality instrument, and advanced calibration features of the aquatech, but with a modern interface, and the recording features of the Mintaka.., maybe just a bit updated. And, obviously NMEA out over USB.
I don't think there is anything like that yet
USB hasn't been a bad experience, it has worked perfectly well and setting it up in expedition and subsequently out to deckman and B&G displays is easy, giving you all the strip chart options you could ever want. With using it in a strip chart i get easy access and good viewing options via my deckscreen/tablet.
but which unit are you connecting via USB - what I have learned.., through using them.., is that not all the instruments are good enough.
can you calibrate it at may different pressure values, or only at one?
how much does the instrument drift?
i am on boats all the time with the B&G barometer connected to the instruments, and going to expedition - i don't trust them at all. some may work.., but i have seen enough that don't work well, that i always just ignore them, and use my own.